Q: What is the energy of a single photon of light with a wavelength of $$500\ \mathrm{nm}$$? (Use $$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J \cdot s}$$ and $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$3.98 \times 10$$^{-19}$$\ \mathrm{J}$$

Question 1

Which of the following statements best describes the Law of Multiple Proportions?

Accepted Answer

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other are in ratios of small whole numbers.

Question 2

A student measures the mass of a sample five times and obtains values that are very close to each other, but all are significantly higher than the actual mass. Which of the following best describes the student's measurements?

Accepted Answer

The measurements are precise but not accurate due to systematic error.

Question 3

Which of the following phase changes is exothermic?

Accepted Answer

Condensation ($$g \rightarrow l)$$

Question 4

A sample of an unknown metal has a mass of 15.0 g and a volume of 2.00 mL. What is the density of the metal?

Accepted Answer

$$7.50\ \mathrm{g/mL}$$

Question 5

Which of the following best explains why isotopes contradict Dalton’s Atomic Theory?

Accepted Answer

Dalton stated that all atoms of a given element have the same mass, but isotopes of an element have different masses.

Question 6

Which of the following is the correct formula to convert a temperature from Celsius to Kelvin?

Accepted Answer

$$K = C + 273.15$$

Question 7

A neutral atom of bromine has an atomic number of 35. If it gains one electron, what is the symbol and charge of the resulting ion?

Accepted Answer

$$\mathrm{Br}^-$$

Question 8

Which experiment provided evidence for the existence of the nucleus in the atom?

Accepted Answer

Rutherford’s gold foil experiment

Question 9

Which of the following statements about the photoelectric effect is correct?

Accepted Answer

Electrons are ejected from a metal only if the incident light has a frequency above a certain threshold, regardless of intensity.

Question 10

What is the energy of a single photon of light with a wavelength of $$500\ \mathrm{nm}$$? (Use $$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J \cdot s}$$ and $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$3.98 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 11

Which set of quantum numbers is NOT allowed for an electron in an atom?

Accepted Answer

$$n = 2,\ l = 2,\ m_l = 0,\ m_s = +\frac{1}{2}$$

Question 12

Which of the following best describes the difference between a cation and an anion?

Accepted Answer

A cation has more protons than electrons, while an anion has more electrons than protons.

Question 13

How many electrons can occupy the $$n = 3$$ principal energy level in an atom?

Accepted Answer

18

Question 14

Which of the following statements about the Bohr model of the atom is correct?

Accepted Answer

Electrons emit photons when they move from higher to lower energy orbits.

Question 15

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of water. How many moles of water does this represent?

Accepted Answer

$$0.500\ \mathrm{mol}$$

Question 16

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Salt water

Question 17

Which property is intensive and which is extensive?

Accepted Answer

Density is intensive; mass is extensive.

Question 18

Which of the following best describes the Heisenberg Uncertainty Principle?

Accepted Answer

It is impossible to simultaneously know both the exact position and exact momentum of an electron.

Question 19

Which of the following statements about electromagnetic radiation is correct?

Accepted Answer

Shorter wavelength light has higher energy than longer wavelength light.

Foundations of Atomic Theory and Electronic Structure: General Chemistry Study Notes

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