Mendeleev i guess. The answer is C
Answer: C. Dmitri Mendeleev
Explanation: Dmitri Mendeleev was the first scientist who initiated the arrangement of elements in the regular pattern which is known as the Periodic table of Elements.
He tried to arrange these elements on the basis of the chemical properties and on the basis of their atomic number.
Atomic number was considered as the basis of the periodic table as it is the most basic and essential property of the elements.
Why do you think the process to create a protected area takes so long?
The process to create a protected area takes a long time because there's numerous things that have to be taken in account and sorted out before the area gets that kind of legal status.
Usually there's people living in the area that is supposed to be protected, though it is mostly small settlements. The people living there are connected with that area, use the resources, and their lives are largely based and dependent on it. In order for any problems to be avoided, these people should all be educated, deals to be made with them, and properly negotiated so that the area wouldn't have any damage, but also them to be able to sustain themselves.
The boundaries of the area are also complicated, it it takes time to sort out what parts should be included and what not. Basically to set the priorities.
People should be employed to protect and take care of the area, so they have to undergo a training, education, and to get familiar with it.
The legalization of the area as such can sometimes too make problems and take some time.
Which of the following statements about air masses is true?
A.
Air masses are areas of condensed water vapor, which are also known as clouds.
B.
Air masses are responsible for creating holes in the ozone layer.
C.
Air masses maintain the same moisture and temperature as they move over new areas.
D.
Air masses are created by patterns of heating and cooling of the Earth's surface.
Answer:
The correct answer is: D. Air masses are created by patterns of heating and cooling of the Earth's surface.
Explanation:
The air masses can be simply be divided into warm and cold ones, further they can be moist or not. The formation of the air masses, be it warm and cold, over the land masses is because of patterns of heating and cooling. This results some areas to produce very large air masses that are cold and dry, like Siberia, or warm and dry large air masses, like Sahara. Also, on a local level there's air masses that develop every day and night, which is noticeable during the night and the morning, where the colder air masses from the mountains move down to the valleys, and the warm air masses from the valleys move up to the mountains. That is a because of the change in the heating and cooling patters that differ during the day and the night.
Answer:
The correct answer is: D. Air masses are created by patterns of heating and cooling of the Earth's surface.
Explanation:
What is the porcent of H in NH3
Answer:
17.65 %.
Explanation:
To calculate the % of H in NH₃:% H = [Atomic mass of (3H)/molar mass of NH₃] x 100 = [(3 x 1.0)/(17)] x 100 = 17.65 %.
A particle that has a negative charge:
A)Electrons
B)Neutrons
C)Protons
D)Non-polar Molecule
Answer:
A) electrons
Explanation:
protons are positive , neutrons are neutral , and electrons are negative , and non-polar does not have a charge . so electrons is correct
The particle that has negative charge is electron
What are Electrons?An electron is a negatively charged subatomic particleElectrons in atoms exist in spherical shells of various radii, representing energy levels. The larger the spherical shell, the higher the energy contained in the electron..
Why Other Options are Incorrect?Neutrons is incorrect because it is totally neutral it neither contains positive charge nor contains negative chargeProtons contains positive charge hence the option is incorrectNonpolar molecule is one whose charge distribution is spherically symmetric when averaged over time
Hence Electrons is the correct option (A)
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Which type of fire is sometimes set as a way to protect a forest?
Surface fire
Explanation;Surface fires are type of forest fires that may burn primarily as a surface fire, spreading along the ground as the surface litter and undergrowth on the forest floor and is engulfed by the spreading flames.They are the easiest fires to put out and cause the least damage to the forest. Surface fires create the least amount of destruction.These fires protects the forest by releasing the nutrients that would otherwise decompose slowly, having little benefit to the ecosystem.Additionally, these fires allow more open spaces for new and different kinds of vegetation to grow and receive sunlight.what is the percentage yield of carbon disulfide if the reaction of 32.0g of sulfur dioxide produces 12.0g of carbon disulfide?
= 63.04 %
Explanation;The balanced equation for the reaction;
5 C + 2 SO2 → CS2 + 4 CO
We can calculate the theoretical yield;
= (32.0 g SO2) / (64 g C/mol) x (1/2) x (76.1418 g CS2/mol)
= 19.035 g CS2 in theory
But;
Percentage yield = Actual yield/theoretical yield × 100%
= (12.0 g) / ( 19.035 g) × 100%
= 0.6304 × 100%
= 63.04%
Final answer:
To calculate the percentage yield of carbon disulfide, we can compare the actual yield to the theoretical yield. Using stoichiometry, we can calculate the theoretical yield based on the given masses of sulfur dioxide and carbon disulfide. The percentage yield is found to be 31.5%.
Explanation:
To calculate the percentage yield of carbon disulfide in this reaction, we need to compare the actual yield (12.0g) to the theoretical yield. The theoretical yield can be calculated using stoichiometry by converting the mass of sulfur dioxide (32.0g) to moles, and then using the mole ratio between sulfur dioxide and carbon disulfide in the balanced equation.
First, let's find the moles of sulfur dioxide:
32.0g SO2 * (1 mol SO2 / 64.06g SO2) = 0.500 mol SO2
According to the balanced equation, 1 mol of SO2 produces 1 mol of carbon disulfide. So, the theoretical yield of carbon disulfide is also 0.500 mol.
Now, we can convert the theoretical yield from moles to grams:
0.500 mol CS2 * (76.14g CS2 / 1 mol CS2) = 38.07g CS2
Finally, we can calculate the percentage yield:
Percentage yield = (Actual yield / Theoretical yield) * 100
Percentage yield = (12.0g / 38.07g) * 100 = 31.5%
Given the name select the correct formula for each ion compound
Please provide more info
The mass per unit volume is substance is called
The mass per volume of a substance is called its density.
The mass per unit volume is substance called density.
Hope this helps
Have a great night
God bless you
- Kayla :)
What is the period of a wave if the wavelength is 100 and the speed is 200
Wavelength and frequency are inversely proportional to each other. ... Even though the wave speed is calculated by multiplying wavelength by frequency, an alteration in wavelength does not affect wave speed. Rather, an alteration in wavelength affects the frequency in an inverse manner.
❤️Hello!❤️ This is simple question and easy to understand.
so first you use a formula to calculate frequency of the wave.
v _ stands for velocity a.k.a speed
f_ stands for frequency which you have to find.
(pronounced lemda)_ stands for wavelength.
Then you gonna place all your values according to you have in the formula as shown then solve for f.
Finally, you use the time formula
where
T_ is period a.k.a time which equal to the reciprocal of frequency or equal to 1/f.
Simply input your values according to the formula and you your answer as 0.5s Hope this helps! ↪️ Autumn ↩️
Elements can be represented by chemical symbols. Which of the following is the correct way to write the chemical symbol for sodium?
Na
hope this helps :)
What is the concentration of a solution?
Concentration Definition. In chemistry, concentration refers to the amount of a substance per defined space. Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration usually is expressed in terms of mass per unit volume.
Concentration = no of moles of solute/solvent
Which statement best describes the use of a chemical indicator in a titration ?
A chemical indicator in a titration experiment must change the color of the solution near the equivalence point.
Thermodynamic Properties
Property Value
c (solid) 0.5 J/g °C
c (liquid) 1.0 J/g °C
c (gas) 2.0 J/g °C
Melting Point −114 °C
Boiling Point 78 °C
How much heat is released when 60.0 g of ethanol cools from 70 °C to 43 °C?
Answer:
1,620 J.
Explanation:
The amount of heat added to a substance (Q) can be calculated from the relation:Q = m.c.ΔT.
where, Q is the amount of heat released from ethanol cooling,
m is the mass of ethanol (m = 60.0 g),
c is the specific heat of ethanol in the liquid phase, since the T is cooled below the boiling point and above the melting point (c = 1.0 J/g °C),
ΔT is the temperature difference (final T - initial T) (ΔT = 43.0 °C – 70.0 °C = - 27.0 °C).
∴ Q = m.c.ΔT = (60.0 g)(1.0 J/g °C)(- 27.0 °C) = - 1620 J.
The system releases 1620 J.Answer:
its 1600 J
Explanation:
i just got it right on the quiz
Which describes an example of genetic engineering?
1) By replacing a defective gene, symptoms of a disease disappear.
2)Vitamin A is added to rice to combat blindness.
3)Two roses are crossbred to create a rose with a certain shade of pink.
4)Overtime,the species developed webbed feet
Answer: 2)Vitamin A is added to rice to combat blindness.
Explanation:
The genetic engineering is a process of manipulation of the genome of the organism by either introducing new genes in an organism's genome or by removing the defective genes. This is basically performed to introduce new traits in an organism or to remove the disease causing genes.
Vitamin A is added to rice to combat blindness is the correct option because genetic engineering will ensure the introduction of the genes which are responsible for secretion of vitamin A in the rice plant as the rice species does not naturally produce vitamin A. This will help in combating the disorder of blindness in humans.
Genetic engineering involves introducing genetic material into organisms to create traits for specific purposes.
By replacing a defective gene, symptoms of a disease disappear.
Genetic engineering involves the artificial incorporation of genetic material from one form of life into another, creating genetically modified organisms (GMOs) like 'golden rice' or 'Bt' corn. These modifications aim to introduce desirable traits into plants for various purposes.
How are meteorites and meteors different?
Meteorites are found in space and meteors are not.
Meteorites usually burn up in the atmosphere, but meteors do not.
Meteorites are larger than meteors.
Meteorites have struck the Earth's surface, but meteors have not.
Meteors are a streak of light. A meteorite is when it hits Earth's surface. So, it would be D.
Final answer:
Meteorites have struck the Earth's surface, but meteors have not. Meteorites are meteoroids that land on Earth, whereas meteors are glowing gases in the atmosphere that do not reach the surface.
Explanation:
Meteorites are meteoroids that survive the journey through the atmosphere and hit the Earth's surface. On the other hand, meteors are the glowing trail of gases formed as meteoroids heat up in the atmosphere but do not reach the Earth's surface.
Meteorites can be found on Earth, providing valuable information about our solar system, while most meteors burn up before reaching the surface. The distinction between meteorites and meteors lies in their fate upon entering the Earth's atmosphere.
how many ml of a 0.50m solution of hno3 solution are needed to make 500 ml of 0.15m hno3
Answer:
150.0 mL.
Explanation:
It is known that the no. of millimoles of HNO₃ before dilution = the no. of millimoles of HNO₃ after dilution.∵ (MV) before dilution = (MV) after dilution.
∴ V before dilution = (MV) after dilution / M before dilution = (0.15 M)(500.0 mL)/(0.50 M) = 150.0 mL.
What is the percent concentration of a sodium fluoride solution made be dissolving 65.4 grams of sodium fluoride in 125.1 grams of water?
Answer:
34.33 %.
34.33 %.
34.33 %.
Explanation:
To calculate the mass percent or weight percent of a solution, you must divide the mass of the solute by the mass of the solution (both the solute and the solvent together) and then multiply by 100 to change it into percent.W% = [(W of solute NaF)/(W of solution)] x 100.
W of solute NaF = 65.4 g.
W of solution = W of solute NaF + W of water = 65.4 g + 125.1 g = 190.5 g.
∴ W% = [(W of solute NaF)/(W of solution)] x 100 = [(65.4 g)/(190.5 g)] x 100 = 34.33 %.
Consider the situation. Scientists have developed an explanation of a phenomenon from several verified hypotheses. The explanation has been confirmed through numerous experimental tests.
Which option best describes this explanation?
A. research question
B. scientific theory
C. scientific law
D.hypothesis
I think its B or D.
scientific theory
hope this helps :)
Answer:
B. scientific theory
Explanation:
The scientific theory explains the phenomenon observed in the natural world. It is based upon the scientific method. To arrive at the scientific theory a hypothesis is formed, experiments are designed and conducted, resulted evaluated, analyzed and conclusions are reached. scientific theory are based upon experiments that are tested under controlled conditions.
In an experiment, shinning which type of light on a strip of metal would be least likely to produce the photoelectric effect?
A. Ultraviolet light
B. Dim blue light
C. Bright red light
D. Bright yellow light
C red light isn't an efficient source of light
Answer:
Bright red light.
Explanation:
The light when strikes on an object has the ability to show the photoelectric effect. Different light has different wavelength that determines their photoelectric effects.
The ultraviolet light emit the large amount of energy whereas the redllight emits the least amount of energy. The bright red light is least likely to produce the photoelectric effect.
Thus, the correct answer is option (C).
If 100.0 ml of HCI stock solution is used to make 500.0-ml of a 0.675 M HCI dilution, what is the molarity of the stock solution ?
Answer:
3.375 M.
Explanation:
It is known that the no. of millimoles of HCl before dilution = the no. of millimoles of HCl after dilution.∵ (MV) before dilution = (MV) after dilution.
∴ M before dilution = (MV) after dilution / V before dilution = (0.675 M)(500.0 mL)/(100.0 mL) = 3.375 M.
18,754kg of methanol which has a density of 0.788g/cm3 what is the volume
Hello
V= m/p when V= volume, m, mass and p the density
then
V=18754000/0,7888
Remember that you first have to convert kg to gr, simply multiplied by 1000.
then
V= 23799492 cm3
Best regards
NEED HELP ASAP
Which statements describe competition for shelter? Check all that apply.
A. Bees work together to construct a beehive.
B. Two prairie dogs fight over underground space.
C. Several monkeys work to create a space for their young.
D. A pack of lions roar to protect their territory from other lions.
E. Penguins push each other to find room on a floating iceberg.
Answers are B, D and E. A and C are cooperation for shelter.
Explanation:
Competition means when more than one person or individual is competing for a certain thing.
For example, two prairie dogs fight over underground space.
This means that both the dogs are fighting to have a house for themselves.
Thus, we can conclude that statements which describe competition for shelter are as follows.
Two prairie dogs fight over underground space.A pack of lions roar to protect their territory from other lions.Penguins push each other to find room on a floating iceberg.What does a particular point on a line of a phase diagram represent ?
Answer:
it is the point where the material turns to gas
Explanation:
Answer: The melting point or boiling point of a substance at a specific pressure
Explanation: That was the correct answer apex.
An elements atomic number is 117 how many electrons would an atom of this element have?
117 because the number of protons and neutrons are the same as the atomic mass.
Final answer:
A neutral atom with an atomic number of 117 would have 117 electrons. The valence shell of element 117 (Tennessine) is likely to have 7 electrons, similar to other halogens, though high atomic number elements can be unpredictable due to their instability.
Explanation:
If an element has an atomic number of 117, it means that a neutral atom of this element would have 117 protons in its nucleus. According to the basic rules of atomic structure, a neutral atom has the same number of protons and electrons. Therefore, an atom of this element would have 117 electrons.
Regarding the valence shell electron configuration, since element 117 (Tennessine, Ts) is in the 17th group of the periodic table and is part of the halogens, its valence shell could be similar to that of other halogens. Considering the periodic trends and the fact that it belongs to the 7th period of the table, its valence shell would likely have 7 electrons. However, due to its high atomic number and unstable nature, the element's chemistry might not entirely follow the trends observed in lighter elements.
In the chemical reaction below, calcium (Ca) and water (H2O) react to form calcium hydroxide (Ca(OH)2) and hydrogen gas (H2).
Ca (s) + 2H2O (l) → Ca(OH)2 (aq) + H2 (g)
Calcium and water are the reactants in this chemical reaction, whereas calcium hydroxide and hydrogen gas are the products that are formed. Once the reaction reaches completion,
A.
the total mass of the products will be greater than the original mass of the reactants.
B.
the total mass of the products will be less than the original mass of the reactants.
C.
the products of the reaction will have changed back into the reactants.
D.
the total mass of the products will be equal to the original mass of the reactants.
Reset Submit
D. the total mass of the products will be equal to the original mass of the reactants
Explanation;According to the law of conservation of mass, matter cannot be created or destroyed. Every chemical equation obeys this Law.Law of conservation of mass is adhered in all chemical equations by ensuring the chemical equation is balanced. This involves the use of coefficients on products and reactants to balance the number of atoms of an element on both sides of a chemical equation.Therefore, according to the Law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants, which is achieved by balancing the chemical equation.Answer:
it is the answer d. the total mass of the products will be equal to the original mass of the reactants
Explanation:
NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Which types of heat transfer involve heat flow from hot objects to colder objects?
A.
convection and conduction, but not radiation
B.
convection and radiation, but not conduction
C.
convection, conduction, and radiation
D.
convection, but not conduction or radiation
A.
convection and conduction, but not radiation
The answer is A, thank you boredpanda for checking my answer probably accendintly.
Hope this helps!
A chemist needs 22.0 grams of phenol, C6H5OH, for an experiment. how many molecules of phenol would this be?
0.234 mol C[tex]C_{6} H_{5} OH[/tex]
The number of molecules would be - 1.410*[tex]10^{23}[/tex] molecules in 22 grams of phenols.
The molecular formula of Phenol is C6H5OH
, Therefore, molecular weight:
= 6(Mass of carbon) + 6(Mass of hydrogen) + 1 (Mass of oxygen)
= 6 × 12.0107 + 6 × 1.00784 + 15.999 × 1
= 94.11
=> The number of moles of phenols:
=> No of mol of phenol = weight/Mwt
[tex]\frac{weight}{molecular\ weight}\\\\= \frac{22}{94.11}\\[/tex]
= 0.234 moles
=> The number of molecules of phenol would be in 22 grams:
molecules = [tex]6.022 \times 10^{23} *\ (number\ of\ moles)[/tex]
[tex]6.022 \times 10^{23} \times (0.234)\\= 1.410 \times 10^{23}[/tex]
Thus, the number of molecules would be - 1.410 [tex]\times 10^{23}[/tex] molecules.
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If the forward reaction is favored in the equilibrium, what will increase?
SELECT AN ANSWER
Blue
Red
Concentration of products
Concentration of reactants
Answer:
Option C:- concentration of products
Explanation:
According to Le Chateleir's principle,
if the forward reaction is favored in the equilibrium then concentration of products will increase and concentration of reactants will decrease.
If the reverse reaction is favored in the equilibrium then concentration of products will decrease and concentration of reactants will increase.
When the forward reaction is favored in a chemical equilibrium, the concentration of products will increase as the equilibrium shifts to the right, in accordance with Le Chatelier's principle.
When a chemical reaction reaches equilibrium and the forward reaction is favored, we observe that the equilibrium shifts to the right or toward the product side. This means that there will be an increase in the concentration of products. In a dynamic equilibrium, when we increase the concentration of the reactants, the system will respond by shifting the equilibrium to the right to use up the excess reactants and produce more products.
This behavior adheres to Le Chatelier's principle, which informs us that the system will adjust to minimize the change, leading to an increase in product concentration until equilibrium is reestablished.
For example, if the concentration of a reactant such as SCN- (aq) is increased, the rate of the forward reaction will increase, leading to a decrease in the concentration of this reactant as it is converted into the product FeSCN²+ (aq), consequently, the concentration of FeSCN²+ will increase as the equilibrium shifts to the right.
Ecosystem services are services provided by
The answer is C) Communities in an effort to beautify local neighborhoods
Answer: nature that benefit mankind
Explanation:
Ecosystem services are the benefits that mankind freely gain from nature and well-functioning ecosystems. For example, agroecosystems, forest ecosystems, grassland ecosystems and aquatic ecosystems. When these ecosystems function well, they provide benefits such as agricultural produce, timber, and aquatic organisms such as fishes and crabs. These benefits together are called 'ecosystem services'.
Why are gases less soluble at higher temperature
As the temperature is increased all the molecules including the gas molecules get more kinetic energy, they move faster, and more of them can escape from the solution when they hit the surface meaning fewer molecules stay inside, hence lower solubility.
Final answer:
The solubility of gases in liquids decreases with rising temperature because added thermal energy increases kinetic energy, enabling the gas molecules to overcome the attraction of the solvent molecules and escape back into the gas phase.
Explanation:
The solubility of gases in liquids is affected by temperature. As temperature increases, the kinetic energy of molecules in both the solvent and the solute also increases. Specifically for gases like HCl, NH₃, and SO₂, which are soluble under standard conditions, an increase in temperature causes these gas molecules to have a greater tendency to escape from the attraction of the solvent molecules and revert to the gas phase due to the rise in kinetic energy. Therefore, this leads to a decrease in their solubility within the solvent.
For example, when we heat a solvent that has a gas dissolved in it, we provide thermal energy that overcomes the attractive forces between the gas and solvent molecules. This process is similar to how increased temperature results in higher vapor pressure in pure liquids because thermal energy overcomes the attractive forces between the molecules, allowing them to enter the gas phase.
In summary, the dissolution of most gases is an exothermic process, meaning it releases heat, but when heat is added to the system, it facilitates the separation of the gas from the solution, thus decreasing gas solubility with the rise in temperature