Answer:
Be (899 kj/mol) , Se (940.9 kj/mol), Ne(2081 kj/mol), He (2370 kj/mol),
Explanation:
For noble gases as they have complete octet so they require high amount of energy to remove the electron.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
what type of reaction is
2A1Br3 +3K2SO4+6KBr +
Al2(SO4)3
Synthesis/Combination
Decomposition
Single Replacement
Double Displacement
or Combustion?
Answer: Double Displacement
Explanation: In a double displacement reaction it is shown through this generic description
AB+ CD => AD + CB
Where A and C are both metals and B and D are nonmetals.
A is Al
B is Br
C is K
D is SO4
In this reaction
Al displaces K to combine with SO4
K combines with Br forming KBr
_C2H + __02 → __CO2 + __HO
Answer: 2C2H + 5O2 => 4CO2 + 2HO
Explanation: The chemical equation is now balanced.
Calculate the atomic mass of element X if there are two isotopes of this element (X-24 and X-28) and 75% of all X atoms are X-28 isotopes.
52 amu
4 amu
27 amu
26 amu
Answer:
Atomic mass = 27 amu
Explanation:
Given data:
Atomic mass of element X= ?
Abundance of X-28 = 75%
Abundance of X-24 = 100 - 75 = 25%
Atomic mass of X-28 = 28 amu
Atomic mass of X-24 = 24 amu
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (75×28)+(25×24) /100
Average atomic mass = 2100 + 600 / 100
Average atomic mass = 2700 / 100
Average atomic mass = 27 amu.
BRAINIEST TO THE ONE WHO ANSWER THIS
1.- Describe the trend in ionization energy as the atomic number increases ACROSS a period.
2.- Describe the trend in ionization energy as the atomic number increases DOWN a group.
Answer:
The statement that best describes the trend in first ionization enery of elements on the periodic table is:
It generally decreases down a group because valence electrons are farther from the nucleus.
The first ionization energy measures how difficult is to release an electron from the outermost shell. The higher the ionization energy the more difficult it is to release an electron, the lower the ionication energy the easier to release an electron.
As the atomic number of the atom increases (which is what happens when you go down a group) the furthest the outermost shell of electrons will be (the size of the atoms increases) and so those electrons require less energy to be released, which means that the ionization energy decreases.
Hope it helps!
Answer:
1. Across a period , the ionization energy increases because the formation of a cation becomes more difficult owing to the increase in nuclear charge.
2. Ionization energy decreases down the group because the outer electrons become progressively separated from the nucleus and so are less tightly held .
Explanation:
Which step is not included in carbon cycle
Your answer would be Transpiration
The higher an electromagnetic wave's frequency, the lower its
O A. speed
O B. energy
O c. wavelength
O
D. amplitude
SURN
Answer:
C)wavelength
Explanation:
if the wavelength of a light wave is shorter, that means that the frequency will be higher because one cycle can pass in a shorter amount of time. ... That means that longer wavelengths have a lower frequency. Conclusion: a longer wavelength means a lower frequency, and a shorter wavelength means a higher frequency!
A certain quantity of ammonium nitrite is separated into its polyatomic components, and each polyatomic ion is then carefully transferred and stored in an individual 100-Liter container. If the container containing ammonium nitrite has a density of 2g/L, how many mols of nitrite are in the second container?
Answer:
5000
Explanation:
you do stuff and more stuff
Is Li2o+h2o=LiOH combustion
Answer: No
Explanation:Combustion is the process where a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water.
Combustion reaction:
CH + O2 => CO2 + H2O
7944/0.024 = _______ give the answer to the correct number of significant figures?
Answer:
330,000
Explanation:
Since there are only 2 significant figures in 0.024 ( and 0.024 is the number with the least number of significant numbers), the answer is 330,000, not 331,000.
Single-crystal sapphire has a melting point of aorund 2323K what is the melting point in degrees Celsius?
Answer: 2050°C
Explanation:
K = 2323K
°C = K — 273 = 2323 — 273
°C = 2050°C
The melting point of single-crystal sapphire when converted from Kelvin to degrees Celsius is approximately 2049.85°C, indicating the strength of the bonds within its crystal structure, akin to diamond and silicon carbide.
Explanation:To convert the melting point of single-crystal sapphire from Kelvin to degrees Celsius, you subtract 273.15 from the Kelvin temperature. Given that the melting point of sapphire is around 2323K, the calculation would be:
2323K - 273.15 = 2049.85°C
Therefore, the melting point of single-crystal sapphire in degrees Celsius is approximately 2049.85°C. This high melting temperature indicates the strength of the bonds within the crystal structure of sapphire, similar to other compounds with diamond or related structures, such as diamond and silicon carbide, which also have high melting points due to their strong covalent bonds.
Will make brainliest
A model of an atom is shown below. Which element is represented by this model of an atom?
Boron (B)
Carbon (C)
Neon (Ne)
Sodium (Na)
Answer:
Boron
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example
In given atomic model we can see that there are five electrons out side the nucleus it means this atomic model is of that element which have atomic number 5 and it is boron.
It has 5 electron 5 proton and 6 neutrons.
It means its atomic number is five and mass number is 5+6 = 11
Which of the following values is equal to 1 micrometer?
0.000001 meter
0.001 meter
1,000 meter
1,000,000 meter
Answer:
its a
Explanation:
Answer:
0.000001
Explanation:
A 18.00 g candy bar is found to contain 11.00 g of sugar. How many mg of sugar does the candy bar contain ?
Answer:
11,000 milligrams
Calculate the kelvin scale equivalent of 123 Celsius?
Answer:
123 Celsius is equal to 396.15 Kelvin scale
Explanation:
2 C6H14 + 19 O2 --> 12 CO2 + 14 H2O
Using the above reaction, how many moles of C6H14 are needed to produce 8.86 moles of water
Answer:
1.27 moles (3 s.f.)
Explanation:
Mole ratio of water: C6H14
= 14:2
= 7:1
This means that to produce 7 moles of water, 1 mole of C6H14 is needed. Or 1/7 mole of C6H14 is needed to produce 1 mole of water. So if you need 8.86 moles of water, 8.86(1/7) moles of C6H14 is needed.
For 8.86mol of water, moles of C6H14 needed
= 8.86/7
= 1.27 moles (3 s.f.)
if you were trying to heat 1g water from temperature of 5C to 6 C, how much heat would be required to do so?
Answer:
The heat required is 4.18 J
Explanation:
First you need to know what is specific heat capacity ,
Specific Heat Capacity : The amount of heat required to raise the temperature of 1 gram of substance by one degree .
The specific heat capacity of water is 4.18 J/gC.
This means that to increase the temperature of 1 gram of water by one degree , 4.18 J of energy is needed.
The formula to calculate the heat is given by :
[tex]q=mc\Delta T[/tex]
q = heat absorbed/emitted
m = mass of the substance
[tex]\Delta T[/tex] = Change in temperature
c = 4.18 J/gC
Here , m= 1 gram
[tex]\Delta T[/tex]= 6 -5 = 1 degree
Put the value in the formula:
[tex]q=mc\Delta T[/tex]
[tex]q=1\times 4.18\times 1[/tex]
q = 4.18 J
Unit conversion :
m = gram
c = J/gram C
T = C
q = mcT = gram x J/gram C x C
q = J
Al2(SO4)3 + BaCl2 balanced equation
Answer:BaCl2 + Al2(SO4)3 -->BaSO4 + AlCl3.
Explanation:
A beaker contains 175.32g of salt, NaCl(58.44g/mol). Water is added until the final volume is 2 liters. The solution should be described as
A. 87.66M
B. 29.22M
C. 3M
D. 1M
E. 1.5M
Answer:
E. 1.5M
Explanation:
because there is total 175.32 g of NaCl dissolved in 2 liter of water, and 58.44 g = 1 mol
so total miles = 175.32/58.32 = 3 moles
now 3 moles are in 2 liter of water, hence one liter contains 3/2= 1.5
Therefore answer is E. 1.5M
Tissues are made up of different types of organs true or false
Answer: False
Explanation: Organs are made up of different tissues
The statement is false. Tissues are made up of similar cells that share a common function. Organs are made from different types of tissues that work together.
Explanation:The statement in the question is false. In biology, tissues are groups of similar cells that have a common structure and function. However, they do not form organs independently. Actually, the hierarchy in biological organization is cells - tissue - organ - organ system.Organs are made up of different types of tissues that work together to perform a specific function or set of functions. For example, the heart is an organ made up of cardiac tissue which allows it to contract and pump blood around the body.
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A pound is approximately 0.45 kilogram. A person weighs 87 kilograms. What is the person's weight, in pounds, when expressed to the correct number
of significant figures?
A.
190 lb
B.
180 lb
C.
52 lb
D. 39 lb
Answer: A. 190 lbs.
Explanation: To find the mass in pounds we will use the following conversion factor: 1 lb = 0.45 kg
Solution:
87 kg x 1 lb / 0.45kg = 193 lbs.
Among the choices 190 lbs is the closest so it is the answer.
Which of the following is NOT a way that biodiversity is important to an ecosystem?
Question 6 options:
A. Biodiversity can increase the rate of extinction.
B. Different types of decomposers are available to break down many types of waste.
C. If one food source goes extinct other food sources are more likely to be available.
D. Biodiversity makes ecosystems more stable.
Answer:
A. Biodiversity can increase the rate of extinction
Explanation:
That statement is false because variety is better for a better ecosystem. With variety more can survive in certain situations that others cant.
Biodiversity can increase the rate of extinction is not a way that biodiversity is important to an ecosystem. Therefore, option A is correct.
What is biodiversity ?The variety and variability of life on Earth is referred to as biodiversity or biological diversity. A measure of variation at the genetic, species, and ecosystem levels is called biodiversity.
Genetic, species, and ecosystem diversity are the typical three levels of biodiversity that are covered. The various genes that each unique plant, animal, fungus, and bacteria have constituted genetic variety. Both inside and between species, it happens.
Conservation of biodiversity safeguards the genetic, microbial, animal, and plant resources needed for agriculture, food production, and ecosystem services like soil nutrient cycling, pest and disease control, preventing erosive processes, and pollination plants and trees.
Thus, option A is correct.
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During a science lab investigating chemical reactions, Mr Grace students place an antacid tablet in a ziplock bag. They recorded the mass of the tablet, 25 g, in the bag, 60 grams. Then they carefully added 50 g of water and quickly seal the bag. The tablet began at this and soon disappeared. The bag was filled with gas. If the total mass of the bag+tablet+water was 135 grams before the reaction, what was the total mass of the bag+liquid+gas after the reaction was completed? A) 60 grams B) 75 grams C) 135 grams D) 270 grams
Answer:
Option- C (135 grams) is the correct answer.
Explanation:
In this experiment the students took tablet of an antacid which when added to water decomposes and produces many products among which some are in gas form. Now, as stated the ziplock bag is quickly sealed after the addition of tablet so it means nine of the gas produced is allowed to escape from the bag.
Therefore, according to law of conservation of mass the mass can neither be created nor destroyed. So, in this experiment there will be no increase in mass because the mass cannot be created and also, there will be no decrease in mass because it can neither be destroyed. So, we will assume that the gas produced is not allowed to escape hence, the total mass of the system (i.e. bag, water, products) will remain the same as they were before the reaction.
Answer:
135 grams
Explanation:
Which career best fits the group of words below?
high voltage lines, low voltage lines, distribution substation
meter reader
geothermal technician
power dispatcher
electrician
Answer:
The answer is "power dispatcher."
Explanation:
"Power dispatchers" are also known as "power distributors." Their field of work is related to controlling the distribution of electricity to the "electrical substations." These substations allow the transmission of electricity to step down from a higher voltage to a lower voltage.
Whenever there is an electrical problem, the power dispatcher also comes into play. They make sure that the power lines are intact and checks for possible damages when typhoons or earthquakes occur.
Thus, this explains the answer.
Answer:
C
Explanation:
Is condensation of ethanol a physical change or a chemical change
Answer: Physical change
Explanation: Condensation is the phase change of a gas to the liquid state. There is no formation of new products so it does not undergoes chemical change. Any phase change is considered a physical change.
Final answer:
Condensation of ethanol is a physical change because it only involves a change in the state of matter without altering the chemical composition of ethanol.
Explanation:
The condensation of ethanol is a physical change. This process involves a change in the state of matter from gas to liquid without altering the chemical composition of ethanol. Like the condensation of water vapor into liquid water, the process is exothermic, releasing energy. However, the ethanol remains chemically identical before and after condensation.
Calcium hydroxide reacts with aluminum sulfate
Assuming that the complete question is the following:
Calcium hydroxide reacts with Aluminum sulfate to form aluminum hydroxide and calcium sulfate. Write the balanced formula unit equation for the reaction.
Then the balanced formula unit equation would be:
3Ca(OH)₂ + Al₂(SO₄)₃ → 2Al(OH)₃ + 3CaSO₄
This is a double replacement reaction, where the cations and anions are interchanged.
Balancing this reaction is based on the Law of Conservation of Mass, which estates that matter is not created nor destroyed, meaning that the number of atoms at the right and the left of the chemical equation needs to be the same. We add coefficients in front of each species that intervenes in the reaction in order to achieve that equality.
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The question is about the chemical reaction between calcium hydroxide and aluminum sulfate, where aluminum hydroxide precipitates and calcium sulfate remains in solution. The aluminum hydroxide can be filtered out and then converted into aluminum oxide for electrolysis to produce metallic aluminum.
Explanation:The student asks about the reaction between calcium hydroxide and aluminum sulfate. In a chemical reaction, calcium hydroxide, represented as Ca(OH)2, would react with aluminum sulfate, which is Al2(SO4)3 to form a precipitate of aluminum hydroxide (Al(OH)3) and a solution of calcium sulfate (CaSO4).
For such a reaction, the balanced chemical equation can be written as:
3Ca(OH)2 (aq) + Al2(SO4)3 (aq) → 2Al(OH)3 (s) + 3CaSO4 (aq)During this process, aluminum hydroxide precipitates from the solution, which can then be removed by filtration. Further treatment, such as heating, can convert the aluminum hydroxide to aluminum oxide (Al2O3), commonly used in the electrolysis process for aluminum production. This process involves dissolving aluminum oxide in a molten mixture of cryolite and calcium fluoride, followed by the application of an electric current to reduce aluminum ions to metallic aluminum at the cathode.
(50 points!) This diagram is a model of the fluorine atom.
How many electrons, protons, and neutrons are in this atom, and how many additional electrons are needed to completely fill the outer shell of this atom?
A.
9 electrons, 11 protons, 9 neutrons; 0 electrons are needed to completely fill the outer shell of this atom
B.
9 electrons, 11 protons, 9 neutrons; 1 additional electron is needed to completely fill the outer shell of this atom
C.
9 electrons, 9 protons, 11 neutrons; 1 additional electron is needed to completely fill the outer shell of this atom
D.
9 electrons, 9 protons, 11 neutrons; 0 electrons are needed to completely fill the outer shell of this atom
Answer:
C
Explanation:
One electron is needed to completely fill the outer shell of this atom.
The number of electrons, protons, and neutrons in the atom are:
Number of electrons = 9
Number of protons = 9
Number of neutrons = 11
The number of additional electron needed is 1
The correct answer to the question is Option C. 9 electrons, 9 protons, 11 neutrons; 1 additional electron is needed to completely fill the outer shell of this atom
Fluorine is a member of the group 17 element called Halogens. They have 7 valence electrons.
NOTE: The nucleus contains the neutrons and the protons while the electrons revolve around the nucleus.
From the diagram given above, the following data were obtained:
Number of electrons = 9
Number of protons = 9
Number of neutrons = 11
Valence electron = 7
Now, we can see that the fluorine atom has 7 valence electrons. Thus, fluorine atom will require 1 electron to complete its outermost shell.
Thus, the correct answer to the question is Option C. 9 electrons, 9 protons, 11 neutrons; 1 additional electron is needed to completely fill the outer shell of this atom
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Near the ceiling of a room air is warmer. The warm air rises because of
Answer:
convection
Explanation:
heat will always rise
Answer:
Convection
Explanation:
Read the chemical equation shown.
Cl2 + 2NaBr → 2NaCl + Br2
Which statement is true about this chemical equation?
Cl (chlorine) is oxidized and Br (bromine) is reduced.
Cl (chlorine) is reduced and Br (bromine) is oxidized.
Na (sodium) is reduced and Cl (chlorine) is oxidized.
Na (sodium) is oxidized and Br (bromine) is reduced.
Redox reactions are the reactions that have been constituting reduction and oxidation. In the chemical equation, chlorine is reduced and bromine is oxidized. Thus, option B is correct.
What is a redox reaction?A redox reaction is a combination of reduction and oxidation reactions. When a reactant loses an electron, then it is called oxidation, whereas the reactant that gains an electron is said to be where the reduction takes place.
The redox reaction is written as,
2 NaBr (aq) + Cl₂ (g) → 2 NaCl (aq) + Br₂ (aq)
Here, oxidation,
2 Br⁻¹ - 2 e⁻ → 2 Br⁰
Reduction,
2 Cl⁰ + 2 e⁻ → 2 Cl⁻¹
From the reaction, NaBr is a reducing agent as it has donated its electron, whereas chlorine gas is an oxidizing agent as it has an accepted electron.
Therefore, in the chemical reaction chlorine is reduced and bromine is oxidized.
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How many atoms are there in 10.2 L of Ar gas at STP?
Answer:
3.011×0²³ atoms of Ar
Explanation:
To find no.of atoms of Ar gas in 10.2 L at STP.
At STP 1 mole of a gas occupies 22.4 L and contains 6.022×10²³ atoms/molecules or ions.
At STP
22.4 L contains 1 mole Ar t
10.2 L contains (10.2÷22.4)×1 Ar
[tex]\frac{1}{2}[/tex] mole Ar contains [tex]\frac{1}{2}[/tex]×6.022×10²³
=3.011×0²³ atoms of Ar
Final answer:
To calculate the number of atoms in 10.2 L of Ar gas at STP, we convert the volume of gas to moles and use Avogadro's number. The number of atoms in 10.2 L of Ar gas at STP is approximately 2.742 x [tex]10^{23}[/tex] atoms.
Explanation:
To determine the number of atoms in 10.2 L of Ar gas at STP, we need to convert the volume of gas to moles and then calculate the number of atoms using Avogadro's number.
First, we convert 10.2 L to moles using the molar volume of a gas at STP, which is 22.4 L/mol.
So, 10.2 L of Ar gas is equal to 10.2 L / 22.4 L/mol = 0.455 moles of Ar gas.
Next, we use Avogadro's number, which is 6.022 x 10^23 atoms/mol, to calculate the number of atoms in 0.455 moles of Ar gas.
So, the number of atoms in 10.2 L of Ar gas at STP is 0.455 moles x 6.022 x [tex]10^{23}[/tex] atoms/mol = 2.742 x [tex]10^{23}[/tex] atoms.
Global warming is a theory accepted by a majority of scientists.
Please select the best answer from the choices provided
OT
OF
Answer:
True
Explanation:
Global warming is a theory accepted by a majority of scientists. This statement is True and correct option is option 1.
What is Global warming?Global warming is the phenomenon of a gradual increase in the temperature near the earth’s surface.
This phenomenon has been observed over the past one or two centuries. This change has disturbed the climatic pattern of the earth.
It is the long-term heating of Earth’s surface observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere.
Therefore, Global warming is a theory accepted by a majority of scientists. This statement is True and correct option is option 1.
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