They are inversely proportional: $$c = \lambda \nu$$

Question 1

Which of the following statements best explains why elements in the same group of the periodic table have similar chemical properties?

Accepted Answer

They have the same number of valence electrons.

Question 2

A neutral atom of potassium has an atomic number of 19 and a mass number of 39. How many neutrons does it contain?

Accepted Answer

$$39 - 19 = 20$$ neutrons

Question 3

Which of the following best describes the result of Rutherford's gold foil experiment?

Accepted Answer

It demonstrated that atoms have a small, dense, positively charged nucleus.

Question 4

Which element is located in Group 16, Period 3 of the periodic table?

Accepted Answer

Sulfur

Question 5

Which of the following correctly describes the trend in atomic size as you move from left to right across a period in the periodic table?

Accepted Answer

Atomic size decreases due to increased nuclear charge pulling electrons closer.

Question 6

A radioactive isotope has a half-life of 5 hours. If a sample initially contains 120 mg, how much remains after two half-lives?

Accepted Answer

$$120 \div 4 = 30 mg$$

Question 7

Which type of radiation has the greatest penetrating ability?

Accepted Answer

Gamma rays

Question 8

Which of the following electron configurations represents a neutral atom of oxygen ($$Z = 8$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^4$$

Question 9

Which of the following best describes the process of nuclear fusion?

Accepted Answer

Two small nuclei combine to form a larger nucleus.

Question 10

Which of the following is a correct nuclear symbol for an isotope of carbon with 6 protons and 8 neutrons?

Accepted Answer

$$^{14}_{6}\mathrm{C}$$

Question 11

Which of the following statements about the electromagnetic spectrum is correct?

Accepted Answer

Gamma rays have the shortest wavelength and highest frequency.

Question 12

A sample of uranium-238 ($$^{238}_{92}\mathrm{U}) $$undergoes alpha decay. What is the nuclear symbol of the product nucleus?

Accepted Answer

$$^{234}_{90}\mathrm{Th}$$

Question 13

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have a full set of valence electrons, making them stable.

Question 14

Which of the following is a property of alkali metals?

Accepted Answer

They are highly reactive and form $$+1$$ ions.

Question 15

Which instrument is commonly used to detect and measure ionizing radiation?

Accepted Answer

Geiger-Müller counter

Question 16

Which of the following best describes the change in ionization energy as you move down a group in the periodic table?

Accepted Answer

Ionization energy decreases because valence electrons are farther from the nucleus.

Question 17

A patient receives a PET scan using a positron-emitting radioisotope. What happens to the positron after it is emitted in the body?

Accepted Answer

It collides with an electron, resulting in the emission of gamma rays.

Question 18

Which of the following best describes the relationship between wavelength ($$\lambda) $$and frequency ($$
u) of $$electromagnetic radiation?

Accepted Answer

They are inversely proportional: $$c = \lambda 
u$$

Question 19

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 20

A sample of a radioisotope has a half-life of 10 years. If the original sample contains 80 g, how much remains after 20 years?

Accepted Answer

$$80 \div 4 = 20 g$$

Atoms, Elements, and Nuclear Chemistry: Study Guide for GOB Chemistry

Study Guide - Practice Questions