Which statement explains how the bands in the crystal of a metal are like atomic orbitals?
Answers
The similarity of the bands in the crystal of a metal to the atomic orbitals can be explained by the band theory of metals. In an atom, when the electrons get excited, the electrons jumps to a higher orbital so as to reach equilibrium. This is analogous to the electrons in the metals which also jumps to another band once excited by an external energy (e.g. electrical energy).
Answer:
D
Explanation:
They both allow electrons to move from lower energy levels to higher energy levels.
Related Questions
What would be the temperature of 0.6 moles of fluorine that occupy 15 L at 2,300 mmHg?
Compared to a 2.0 M aqueous solution of NaCl at 1 atmosphere, a 3.0 M aqueous solution of NaCl at 1 atmosphere has a(1) lower boiling point and a higher freezing point (2) lower boiling point and a lower freezing point (3) higher boiling point and a higher freezing point (4) higher boiling point and a lower freezing point
Persamaan kimia bagi magnesium
Cause and effect of local winds?
Answers
The question is incomplete, this is the complete question;
In the process of attempting to characterize a substance, a chemist makes the following observations. Which are physical properties and which are chemical properties?
(a) The substance is a silvery white, lustrous metal.
(b) The substance melts at 649 ∘C
(c) The substance boils at 1105 ∘C.
(d) The density of the substance at 20 ∘C is 1.738 g/cm³.
(e) The substance burns in air, producing an intense white light.
(f) The substance reacts with chlorine to give a brittle white solid.
(g) The substance can be pounded into thin sheets or drawn into wires.
(h) The substance is a good conductor of electricity.
Answer:
(a) Physical
(b) Physical
(c) Physical
(d) Physical
(e) Chemical
(f) Chemical
(g) Physical
(h) Physical
Explanation:
(a) The substance is a silvery white, lustrous metal - is appearance which is physical.
(b) The substance melts at 649 ∘C metling point is a physical measurement
(c) The substance boils at 1105 ∘C boiling point is a physical measurement
(d) The density of the substance at 20 ∘C is 1.738 g/cm3 how heavy a substance is,is physical.
(e) The substance burns in air, producing an intense white light. Burning is a chemical change. It is a reaction of a substance with oxygen
(f) The substance reacts with chlorine to give a brittle white solid. This is a chemical reaction as the question says.
(g) The substance can be pounded into thin sheets or drawn into wires. Ductility is a physical change, the substance remains chemically unchanged
(h) The substance is a good conductor of electricity. Any conductivity is physical, the substance remains chemically unchanged
Final answer:
The substance in question is likely a pure metal, more specifically Magnesium, because of its documented properties such as lustrous appearance, ability to be drawn into wires, and high electrical conductivity. Its properties like high melting and boiling points and its reactions suggest it could be from Group 1, but its ability to be formed into sheets and wires and its high conductivity suggest it's not an ionic compound like sodium chloride.
Explanation:
The substance described in the question seems to be an example of pure metal due to the properties like lustrous appearance, ability to be drawn into wires or pounded into sheets, and high conductivity of electricity. However, some of the properties like reaction with chlorine, production of intense white light upon burning in air, and its high melting and boiling points suggest that it could be a Group 1 element such as sodium or potassium, which are known for these characteristics. Coupled with information of its density and its ability to form brittle white solid upon reaction with chlorine, it seems to likely be Magnesium, a silvery-white lustrous metal.
Furthermore, ionic compounds like sodium chloride have high melting and boiling points, conduct electricity when molten, and ions are freed to move allowing conductivity. However, such compounds, unlike pure metals, cannot be drawn into wires or pounded into sheets and are usually brittle solids, which would make it less likely that the substance in question is an ionic compound.
The most confident identification will be based on the substance's observed physical and chemical properties and their comparison to known properties of pure metals and ionic compounds.
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(2) 119 atomic mass units
(3) 198 atomic mass units
(4) 277 atomic mass units
Answers
Protons have a relative mass of 1
Gold-198 is a radioactive isotope of gold, which means it has a different number of neutrons, but the same number of protons and electrons
So the answer is (1) 79 atomic mass units
The total mass of protons in a gold-198 atom is about 79 atomic mass units. This calculation considers the 79 protons, each with a mass of approximately 1 amu.
The correct answer is option 1.
The total mass of protons in an atom of gold-198 is approximately 79 atomic mass units. This is determined by considering the number of protons in the nucleus, which is 79 for gold-198. Each proton has a mass of approximately 1 atomic mass unit (amu). Therefore, multiplying the number of protons by the mass of one proton yields the total mass of the protons.
In the case of gold-198:
Total mass of protons = Number of protons × Mass of one proton
Total mass of protons = 79 protons × 1 amu/proton
Hence, the total mass of protons in an atom of gold-198 is approximately 79 atomic mass units.
In summary, the calculation involves recognizing that the mass number of an isotope is the sum of protons and neutrons. In this specific case, gold-198 has 79 protons, and the total mass of its protons is around 79 atomic mass units.
Therefore, from the given options the correct one is 1.
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a. True
b. False
Answers
Answer:
It's true
Explanation:
An example can be observed when the people add salt on the road surface to avoid icing. The salt water mixture is frozen at approximately a temperature of -21°C and not at a temperature of 0°C as it would be in the case of water. Salt when dissolved in water releases heat, thereby contributing to defrost ice. This is the same principle that is used for car antifreeze, which is to lower the freezing point.
PLZ HELP AND SHOW YOUR WORK AND PLZ EXPLAIN TO ME SO I CAN DO OTHER QUESTIONS RELATED TO THIS
Answers
Alright, so the start point is the 2.6cm³. Next you use the density to find the amount in grams. The density can be written out as an identity which in this case would be 0.97gNa=1cm³Na. So you have this equation
2.6mL Na × ≈ 2.5g Na
Remember that 1cm³=1mL and that all answers must follow the rules of significant figures and rounding.
Final answer:
The mass of the sodium sample, calculated using the formula Mass = Density x Volume, is approximately 2.52 grams.
Explanation:
To find the mass of the sodium sample, you can use the formula Density = Mass / Volume. In this case, we know that the density of sodium is 0.97g/cm3 and the volume of the sample is 2.6 cm3. You can rearrange the equation to solve for mass which gives us Mass = Density x Volume.
So if you multiply the density of sodium with the volume of the sample, i.e., 0.97g/cm3 x 2.6 cm3, it results in a mass of approximately 2.52 grams.
So, the mass of the sodium sample is approximately 2.52 grams.
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Answers
We have,
Atomic mass = no. of protons + no. of neutrons
Now, we know, protons never change.....so the only thing that changes is neutrons if we want different atomic mass.
Soooooooo,
The answer is "D. A form of an atom with a different number of neutrons"
The answer is not A. because same element with different number of electron is ion.
The answer is not B. because if it has different number of proton....it is going to be a different element. Just like our fingerprints, we can say that protons are fingerprints of element. No. of protons never change.
The answer is not C. because again talking about electrons.
Answer:
D. A form of an atom with a different number of neutrons.
Explanation:
An Isotope has an equal number of protons but different numbers of neutrons in their nuclei.
Hope it helped!
(2) decreased temperature and decreased pressure
(3) increased temperature and increased pressure
(4) increased temperature and decreased pressure
Answers
The changes in temperature and pressure will cause this sample to behave more like an ideal gas by increased temperature and decreased pressure. Hence option 4 is correct.
What is ideal gas?
Ideal gas is defined as a gas that physically behaves in accordance with the ideal, or general, gas law, which is a certain idealized relationship between pressure, volume, and temperature. The ideal gas law can be used to calculate the volume of gases that are produced or used. The ideal-gas equation is frequently used in chemical equations to convert between volumes and molar values.
Ideal gases are those that have little volume and no intermolecular forces. Real gas must have intermolecular attractions and volume in order to exist. At low pressure and high temperature, a genuine gas will act as it should.
Thus, the changes in temperature and pressure will cause this sample to behave more like an ideal gas by increased temperature and decreased pressure. Hence option 4 is correct.
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Answer : The correct option is, (4) increased temperature and decreased pressure
Explanation :
The conditions for ideal gas are, it has no intermolecular attractions and have negligible volume.
The ideal gas equation is,
The conditions for real gas are, it has intermolecular attractions and have volume.
The real gas equation is,
A real gas behave ideally at high temperature and low pressure conditions.
From the given options, option (4) increased temperature and decreased pressure is the correct option.
Hence, increased temperature and decreased pressure this sample to behave more like an ideal gas.