Question 1

Which of the following statements best describes the difference between an element and a compound?

Accepted Answer

An element is composed of only one type of atom, while a compound is made of two or more different elements chemically bonded together.

Question 2

Which four elements make up the majority of the human body by mass?

Accepted Answer

Carbon, oxygen, nitrogen, and hydrogen

Question 3

A neutral atom of sodium ($$\mathrm{Na}) $$has an atomic number of 11. How many electrons does it have?

Accepted Answer

$$11$$

Question 4

Which of the following best explains why electrons in the outermost shell (valence shell) are important in chemical bonding?

Accepted Answer

They determine the chemical reactivity and bonding properties of the atom.

Question 5

Which of the following is the correct electron configuration for a neutral oxygen atom ($$\mathrm{O}$$, atomic number $$8$$)?

Accepted Answer

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

Question 6

Which type of chemical bond involves the sharing of a pair of valence electrons between two atoms?

Accepted Answer

Covalent bond

Question 7

What is the main difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 8

Which statement about the periodic table is correct?

Accepted Answer

Elements in the same column (group) have similar chemical properties because they have the same number of valence electrons.

Question 9

A hydrogen atom forms a single covalent bond with another atom. Which of the following best describes this bond?

Accepted Answer

Both atoms share one pair of electrons.

Question 10

Which of the following molecules contains a double covalent bond?

Accepted Answer

$$\mathrm{O}_2$$

Question 11

Which of the following best describes a hydrogen bond?

Accepted Answer

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Question 12

Which of the following is true about chemical reactions in biological systems?

Accepted Answer

They rearrange atoms to form new molecules, but the total number of atoms is conserved.

Question 13

Which of the following best explains why carbon is able to form such a wide variety of molecules?

Accepted Answer

Carbon can form up to four covalent bonds with other atoms.

Question 14

Which of the following is a correct statement about electron shells?

Accepted Answer

Electrons in shells farther from the nucleus have higher energy.

Question 15

Which of the following is the best example of a real-world application of electron geometry?

Accepted Answer

The shape of water molecules determines their ability to dissolve salts.

Question 16

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 17

Which of the following best describes the process of cellular respiration?

Accepted Answer

It is a process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Question 18

Which of the following is a consequence of the law of conservation of matter in chemical reactions?

Accepted Answer

The total mass of reactants equals the total mass of products.

Lecture 2 Transcript

스터디 가이드 - 연습 문제