Question 1

Which of the following statements best describes an electrolyte?

Accepted Answer

A compound that conducts electricity when molten or dissolved in water.

Question 2

During electrolysis, which electrode is positively charged?

Accepted Answer

Anode

Question 3

Which experiment led to the discovery of the electron?

Accepted Answer

Thomson's cathode ray experiment

Question 4

What is the charge and approximate mass (in atomic mass units) of a beta particle?

Accepted Answer

Charge: $$1-$$, Mass: $$\frac{1}{1837} u$$

Question 5

Which of the following best explains the main finding of Rutherford’s gold foil experiment?

Accepted Answer

Atoms have a small, dense, positively charged nucleus.

Question 6

How many neutrons are in the nucleus of $$^{238}_{92}U$$?

Accepted Answer

$$146$$

Question 7

Which of the following nuclear symbols represents an isotope of the same element as $$^{18}_8X$$?

Accepted Answer

$$^{16}_8X$$

Question 8

What is the electron configuration for fluorine?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^5$$

Question 9

Which group in the periodic table is characterized by a valence electron configuration of $$ns^2np^5$?

Accepted Answer

Halogens

Question 10

Which of the following statements about metals is correct?

Accepted Answer

They are malleable, ductile, and conduct electricity.

Question 11

Which subatomic particle has a mass of approximately $$1 u $$and a charge of $$1+$$?

Accepted Answer

Proton

Question 12

What is the main difference between isotopes of the same element?

Accepted Answer

They have different numbers of neutrons.

Question 13

Which of the following best describes a cation?

Accepted Answer

A positively charged ion

Question 14

Which of the following is a correct electron configuration for magnesium ($$Z=12$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$

Question 15

Which of the following best describes the role of valence electrons in chemical reactions?

Accepted Answer

They are gained, lost, or shared during chemical reactions.

Question 16

Which of the following is a real-world application of artificial photosynthesis?

Accepted Answer

Generating hydrogen fuel from water using sunlight

Question 17

A sample contains $$^{14}_6C$$ and $$^{12}_6C. $$What do these isotopes have in common?

Accepted Answer

Same number of protons

Question 18

Which of the following best describes a metalloid?

Accepted Answer

An element that demonstrates properties of both metals and nonmetals

Question 19

Which of the following is the correct order of filling for the first three principal energy levels according to the quantum model?

Accepted Answer

$$1s \rightarrow 2s \rightarrow 2p \rightarrow 3s \rightarrow 3p$$

Question 20

Which of the following best describes the relationship between groups in the periodic table and valence electrons?

Accepted Answer

Elements in the same group have the same number of valence electrons.

Atomic Structure and Electron Configuration: Foundations of Chemistry

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