A phase diagram assumes ______ is kept constant
Marie Curie was the recipient of two Nobel Prizes—a shared prize in physics and an individual prize in chemistry. Her chemistry prize was for discovering two new elements, polonium and radium. For what did she, her husband, and Henri Becquerel receive the physics prize?
-The discovery that radioactivity is an extensive property that can be measured precisely.
-The discovery that certain substances can phosphoresce.
-The discovery that radioactivity is caused by the decay of unstable atomic nuclei.
-The discovery that radioactivity can ionize gas in a chamber.
Does elements in group 2 lend electrons
Yes, Group 2 elements, the alkaline earth metals, lose two electrons to form +2 ions, achieving a noble gas electron configuration, and are typically found as compounds due to their reactivity.
The elements in Group 2 of the periodic table are known as the alkaline earth metals. These elements, which include beryllium, magnesium, calcium, strontium, barium, and radium, have two electrons in their outermost energy level.
In chemical reactions, these Group 2 elements tend to lose two electrons to achieve a noble gas configuration, resulting in a +2 oxidation state. This is because they seek to have a full valence shell, similar to the nearest noble gas in the periodic table.
Group 17 elements (halogens) aim to gain one electron to complete their valence shells, while Group 14 elements have the ability to gain or lose four electrons depending on the context. Group 1 elements, also known as alkali metals, readily lose one electron in chemical reactions.
The chemical reactivity of alkaline earth metals is significant, but not as high as their Group 1 counterparts, due to the higher energy required to remove two electrons. Yet, they are reactive enough that they are not found free in nature, only in compound forms. The reactivity and the +2 oxidation state dominate the chemistry of Group 2 elements.
Selenium has six valence electrons. What is the valence of selenium?
Answer:
Two electrons because you need 8 electrons to make a atom stable and selenium has 6 electrons.
Explanation:
The valence of selenium, typically -2, refers to its combining power based on its six valence electrons with the configuration 4s²4p⁴. In compounds, selenium tends to gain two electrons to fill its valence shell.
Explanation:The valence of selenium is the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with.
Selenium has six valence electrons, as indicated by its valence electron configuration: 4s²4p⁴. This means in the fourth energy level (n = 4 shell), selenium has a total of six electrons that can interact with other atoms to form chemical bonds. The valence of selenium can vary depending on the type of compound it forms; however, it is typically -2, as it often seeks to gain two electrons to fill its valence shell and achieve a stable noble gas configuration.
A student attempted to identify an unknown compound by the method used in the experiment. She found that when she heated the sample weighing 0.4862g, the mass barely changed, dropping to 0.4855g. When the product was converted to a chloride, the mass went up to 0.5247g. Is the sample a carbonate? What are the two compounds that might be the unknown?
Answer:
The sample is a carbonate.
The unknown samples are Na2CO3 and K2CO3.
Explanation:
Let's assume ,the sample is Na2CO3.
Na2CO3 produces 2 moles of NaCl via formation of Na2O
Number of moles of NaCO3= 0.48262g/106gmol= 4.586×10^-3mol
Mass of NaCl= 2(4.586×10^-3)×58.5=0.536g
Let's assume the sample is K2CO3
K2CO3 produces2 moles of KCl
Number of moles of K2CO3= 0.4862g/138.21gmol
Number of moles= 3.517×10^-3mol
Mass of KCl formed= 2(3.517×10^-3)×74.55=0.5246g
Alpha particles cannot penetrate deeply into solids because they _____.
have low mass
have high mass
have low velocity
have high velocity
have no mass
Answer: Option (c) is the correct answer.
Explanation:
A particle that contains two protons and two neutrons bounded together is known as an alpha particle.
It is known that an alpha particle has a large mass and due to this they travel very slowly. As a result, they tend to have low velocity.
Hence, we can conclude that alpha particles cannot penetrate deeply into solids because they have low velocity.
Alpha particles can't penetrate deeply into solids due to their high mass. Their large size slows their speed of movement and intensifies their interaction with other atoms, further limiting their penetrating power.
Explanation:
Alpha particles cannot penetrate deeply into solids because they have high mass. An alpha particle is a particle consisting of two protons and two neutrons, which gives it a relatively heavy mass. This high mass limits the speed at which it can move and the distance it can travel, especially in a dense medium like a solid. To put it in perspective, imagine trying to throw a heavy ball through a heavy curtain - the heavier the ball, the less distance it will cover within the curtain. Similar is the case with alpha particles. These particles also have a positive charge, which makes them intensely interactive with other atoms, further limiting their penetration power.
Learn more about Alpha particles here:https://brainly.com/question/24276675
#SPJ6
Why are carbon compounds that contain mercury and a greater environment concern than elemental mercury? ...?
How does the absorption of ultraviolet radiation by the ozone layer help sustain life? a. This process helps maintain the temperature of the Earth. b. It keeps a low level of harmful ultraviolet radiation from reaching living organisms. c. This process keeps ozone concentrations in the troposphere at lower levels. d. All of the above are true.
Answer: d. All of the above are true.
Explanation: Ozone is a protective shield present in earth's stratosphere which absorbs the harmful radiations from the sun and thus keeps a low level of harmful ultraviolet radiation from reaching living organisms.
As the sun rays are absorbed by the ozone layer, not all the sun rays reach the earth's surface and thus the temperature of the earth is also maintained.
The ozone present in the troposphere also called as ground level ozone is harmful as it can trigger a variety of health problems and is formed by reactions of pollutants from vehicular emissions in the presence of sunlight. Thus ozone in stratosphere blocks the sunlight and thus prevents the formation of ground level ozone.
Thus all the statements are true.
COMPARE AND CONTRAST
PROPANE AND HEXANE ...?
Which is true about batteries?
A. They all contain graphite rods and zinc electrodes.
B. They all contain parallel cells that increase energy output.
C. They always contain different cells that work together to produce energy.
D.They often have identical cells in series to increase energy output
Answer:
D.They often have identical cells in series to increase energy output
Explanation:
lol i stg thats the answer just took quiz on edge
_____ is a control mechanism that intensifies an earlier reaction. A sensory receptor An effector Negative feedback Positive feedback
The sensory receptors are nerve endings or specialized cells able to capture internal or external stimuli, and generate in response nerve impulses.
The answer is: A sensory receptor.
How many total atoms are in 0.240 g of P2O5?
To calculate the total number of atoms in 0.240 g of P2O5, you need to convert the mass to moles and then use Avogadro's number to find the total number of atoms.
Explanation:To determine the total number of atoms in 0.240 g of P2O5, you first need to calculate the number of moles of P2O5 using its molar mass. The molar mass of P2O5 is 141.9446 g/mol. You can use the formula: moles = mass / molar mass. Plugging in the values gives: moles = 0.240 g / 141.9446 g/mol = 0.00169 mol.
Next, use Avogadro's number (6.022 x 10^23 atoms/mol) to calculate the total number of atoms. Multiply the number of moles by Avogadro's number:
total atoms = 0.00169 mol x 6.022 x 10^23 atoms/mol = 1.02 x 10^21 atoms.
Differentitate reversible and irreversible process
Why is lewis electron-dot diagrams more suitable than electron-shell diagrams illustrating chemical bonds
The Lewis electron dot diagrams are more suitable as they show bonding and lone pair present on atoms.
What are Lewis electron dot diagrams?These are the diagrams depicting bonding between atoms in a molecule as well as the lone pair present on the atoms.It can be drawn for any covalently bonded molecule as well as for co-ordination compounds.
It shows each atom and its position in the molecule using chemical symbol.Formal charge is used for description and comparison of resonance structures.
Although it fails to explain the cause of covalent bond formation and even geometry of molecule.It does not explain the release of energy during formation of covalent bonds.It also breaks the octet rule in case where central atom has more than eight electrons in its valence shell.
They do not account for aromaticity and nor the magnetic behavior and nature of force of attraction.
Learn more about Lewis electron dot diagrams here:
https://brainly.com/question/2295099
#SPJ2
To fulfill the octet rule electron sharing leads to ____ electrons around each atom?
A. 4
B. 5
C. 6
D. 8
In a machine shop, two cams are produced, one of aluminum and one of iron. Both cams have the same mass. Which cam is larger? (a) the aluminum cam (b) the iron cam (c) Both cams have the same size. ...?
Answer:
A - The aluminum can
Explanation:
Aluminum has a lower density than Iron does.
Imagine having a beachball sized ball of both aluminum and iron... The aluminum ball would be nice and light but that iron ball would definitely crush your toes if you dropped it on your foot! Even if they're the same exact size, they have totally different weights.
Why is charcoal a limited drawing medium?
what did paleomagnetism give strong evidence for A. Pangaea B. earth quakes C. Sea floor spreading D. magnetic storms
Answer: The correct answer is (B).
Explanation:
Paleomagnetism : it is a branch of geophysics which deals with study of magnetism induced in rocks by the magnetic field of earth during their time of formation. It strongly supports the theory of tectonic plates by studying magnetic field around the oceanic ridges.
When two plates rub against with each other earthquake is caused. Hence, it will be obvious to say that paleomagnetism give strong evidence for earth quakes.
Why does hot air rise and cold air sink??
Explanation:
In hot air, molecules have more kinetic energy and due to this they move from one place to another. As a result, there occurs more number of collisions between the molecules. Due to this molecules of hot air tend to rise.
Whereas when air is cold then its molecules are closer to each other. As a result, they do not have enough kinetic energy and they do not move from their initial position.
Hence, cold air sinks because of lack of movement in its molecules.
Hot air is less denser than cold air, which is why hot air rises and cold air sinks.
The invisible gaseous cloud that envelops the Earth and reaches into space is called air. About 78% of it is nitrogen, 21% is oxygen, and the remaining 2% or so is made up of different contaminants, water vapour, carbon dioxide, and other trace gases.
Air molecules move more quickly when it warms near the surface of the Earth or on the first level of a building, producing more space between them and making the air less dense than the cooler air above it. Cooler, more dense air sinks while warmer, less dense air rises. Since cooler air's molecule bonds absorb less energy than hot air's, cooler air is denser and hence heavier.
To know more about air, here:
https://brainly.com/question/33300333
#SPJ6
what is a double bond? A. a total of two covalent bonds between molecules. B. two covalent bonds between adjacent atoms in a molecule. C. two covalent bonds between adjacent molecules
A double bond is a type of covalent bond in which two pairs of electrons are shared between two adjacent atoms in a molecule, making it stronger than a single bond.
Explanation:A double bond is a form of covalent bond where two pairs of electrons are shared between two atoms. In other words, the correct answer to your question is: B. two covalent bonds between adjacent atoms in a molecule. For example, in a molecule of formaldehyde (CH₂O), the carbon atom forms a double bond with the oxygen atom. Similarly, two carbon atoms would form a double bond in ethylene (C₂H4).
Be aware that each bond indicates a sharing of electrons between atoms. Two electrons are shared in a single bond, whereas, four electrons are shared in a double bond, thus making it stronger than a single bond.
Learn more about Double Bond here:https://brainly.com/question/34048294
#SPJ3
Explain how line spectra are used to identify elements and what they indicate about atoms
Electron transitions from higher to lower energy levels cause emission of energy in the form of electromagnetic waves, each with their own specific wavelength. Because the energy levels of elements are quantized, each transition has a specific energy difference. The collection of these transitions makes up the emission spectrum and each spectrum is unique to a specific element, allowing identification.
I WIll upvote for answer
Balance the following reaction Fe^2 O ^3 +HCI+FeCI^3+H^2O
Mexico City has an elevation of 7400 ft above sea level. Its normal atmospheric pressure is 589 mm Hg. At what temperature does water boil in Mexico City?
Final answer:
The boiling point of water in Mexico City, with an elevation of 7400 ft and an atmospheric pressure of 589 mm Hg, is lower than the sea level boiling point of 100°C. It would be approximately between 90°C and 95°C, although a nomogram or the Clausius-Clapeyron relation would be needed for a precise value.
Explanation:
At higher altitudes, such as Mexico City's elevation of 7400 ft, the atmospheric pressure is significantly lower than at sea level. This decreased pressure results in a lower boiling point of water. While the boiling point of water is 100°C at sea level (760 mm Hg), in Mexico City with an atmospheric pressure of 589 mm Hg, the boiling point is reduced. Based on Table 10.1.4, we can infer that as the altitude increases in places like Mexico City, the boiling point of water decreases. From Table 10.4.1, for example, we notice that at an elevation similar to Mexico City's, the boiling point can be several degrees lower than 100°C. Unfortunately, without the specific data for 589 mm Hg from these tables, we cannot give the exact boiling point temperature, but it would typically be between 90°C and 95°C.
To determine the exact boiling point at a specific altitude and pressure, such as Mexico City's, one would often use a nomogram or a formula derived from the Clausius-Clapeyron relation, which correlates temperature and pressure for the phase change between liquid and gas. To obtain a precise value for Mexico City, it is advisable to consult such a nomogram designed for this purpose.
how many sigma and pi bonds are there in phenol?
Phenol rocks 9 sigma (6 C-H, C-O, 2 O-H) and 3 pi bonds (1 C=O, 3 benzene ring).
There are 9 sigma bonds and 3 pi bonds in a phenol molecule.
Here's the step-by-step breakdown:
1. Sigma bonds:
Each single bond between carbon and hydrogen atoms is a sigma bond. There are 6 C-H bonds in the benzene ring, so there are 6 sigma bonds from these.There is one C-O single bond between the benzene ring and the hydroxyl group. This contributes another sigma bond.The O-H bond in the hydroxyl group is also a sigma bond.2. Pi bonds:
The double bond between the carbon and oxygen atoms in the hydroxyl group consists of one sigma bond and one pi bond. So, there is one pi bond here.The benzene ring has a special delocalized structure with alternating single and double bonds. However, each of these bonds still involves one sigma bond and one pi bond. There are 3 double bonds in the benzene ring, so there are 3 pi bonds from these.Therefore, in total, there are 9 sigma bonds (6 from C-H, 1 from C-O, 2 from O-H) and 3 pi bonds (1 from C=O, 3 from benzene ring) in a phenol molecule.
The complete question is here:
How many sigma and pi bonds are there in phenol?
Energy is the ability to do
What is the outermost layer of the earth?
Consider the following reaction:
2CH3OH(g)→2CH4(g)+O2(g)ΔH=+252.8kJ
Calculate the amount of heat transferred when 27.0g of CH3OH(g) is decomposed by this reaction at constant pressure.
If someone could help me with the steps I can figure it out on my own, thank you so much
Final answer:
To find the heat transferred, convert 27.0g CH3OH to moles, use the reaction's stoichiometry to determine heat per mole, and then multiply by the moles of CH3OH. The total heat transferred is 211.7 kJ.
Explanation:
To calculate the amount of heat transferred when 27.0g of CH3OH(g) is decomposed by the given reaction at constant pressure, follow these steps:
Convert the mass of CH3OH to moles using its molar mass (32.04 g/mol for CH3OH).Use the stoichiometry of the reaction to determine how much heat is produced per mole of CH3OH decomposed.Multiply the number of moles of CH3OH by the enthalpy change (ΔH) given for the reaction to find the total heat transferred.Here's how to apply these steps:
Number of moles of CH3OH = 27.0 g / 32.04 g/mol = 0.842 moles.The reaction shows that ΔH for the decomposition of 2 moles of CH3OH is +252.8 kJ.Heat transferred = 0.842 moles * (252.8 kJ / 2 moles) = 211.7 kJ.The heat transferred when 27.0 g of CH3OH(g) is decomposed by this reaction at constant pressure is 211.7 kJ.
some small hybrid cars and sport utility vehicles also have spoilers.what is their purpose? Is it the same or different from the spoiler on a sports car?
Spoilers in small hybrid cars, SUVs, and sports cars aim to reduce lift and drag and improve the grip of the car on the road. They are crucial for sports cars due to the high speeds involved. However, small hybrid cars and SUVs, contribute more towards aesthetics and fuel efficiency, but the principle of operation remains the same.
Explanation:Spoilers are used in vehicles, including small hybrid cars and sport utility vehicles (SUVs), as well as sports cars, primarily to reduce lift and drag, and enhance the car's road grip. Generally, spoilers work on the principle of aerodynamics. For sports cars, in particular, the spoiler becomes more significant at high speeds, redirecting air flows to create a downward force that stabilizes the car, enhancing safety during high-speed maneuvers.
Although the purpose is fundamentally the same across all vehicles, the importance of spoilers may vary. In sports cars, with their high-speed indulgence, spoilers are essential components. On the other hand, for small hybrid cars and SUVs, brackets are used more for aesthetic appeal and fuel efficiency. However, the basic function of a spoiler in either scenario remains—to control airflow.
Learn more about Spoilers here:https://brainly.com/question/30707740
#SPJ12
how many moles are in 22 grams of Argon
Answer:
There are 0.5507 moles in 22 grams of argon.
Explanation:
Mass of argon gas = m = 22 grams
Molar mass of an argon gas = M = 39.95 g/mol
Moles of argon gas = n
[tex]n=\frac{m}{M}[/tex]
[tex]n=\frac{22 g}{39.95 g/mol}=0.5507 mol[/tex]
There are 0.5507 moles in 22 grams of argon.
Name the following ionic compounds involving ionic bonds