$$\text{Atomic mass} = \text{Number of protons} + \text{Number of neutrons}$$

Question 1

Which of the following best describes a compound?

Accepted Answer

A substance consisting of two or more different elements combined in a fixed ratio

Question 2

Approximately what percentage of living matter is composed of the elements carbon, hydrogen, oxygen, and nitrogen?

Accepted Answer

96%

Question 3

Which subatomic particle is responsible for the chemical behavior of an atom?

Accepted Answer

Electron

Question 4

If an atom has 8 protons, 8 neutrons, and 8 electrons, what is its atomic mass?

Accepted Answer

$$16$$

Question 5

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 6

Which type of bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Question 7

What is the main difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

Electrons are shared unequally in polar covalent bonds

Question 8

Which of the following statements about hydrogen bonds is correct?

Accepted Answer

They are weak bonds formed between a hydrogen atom and an electronegative atom

Question 9

Which element is most likely to form an ionic bond with sodium ($$Na$$)?

Accepted Answer

Chlorine ($$Cl)$$

Question 10

What is the formula for calculating the atomic mass of an atom?

Accepted Answer

$$	ext{Atomic mass} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 11

Which of the following best explains why oxygen is highly electronegative?

Accepted Answer

Oxygen has a high tendency to attract electrons due to its high number of protons and small atomic radius

Question 12

Which of the following is true about valence electrons?

Accepted Answer

They are found in the outermost shell and determine chemical reactivity

Question 13

A molecule of water ($$H_2O) is $$held together by which type of bond?

Accepted Answer

Polar covalent bonds

Question 14

Which of the following best describes a cation?

Accepted Answer

An ion with a positive charge

Question 15

Which statement about chemical reactions is correct?

Accepted Answer

Reactants are transformed into products by making and breaking chemical bonds

Question 16

Which of the following is a trace element essential for life?

Accepted Answer

Iron ($$Fe)$$

Question 17

Which type of chemical bond is generally the strongest?

Accepted Answer

Covalent bond

Question 18

What is the main function of energy in biological systems?

Accepted Answer

The ability to do work

Question 19

Which of the following best describes chemical equilibrium?

Accepted Answer

The point at which the rate of the forward reaction equals the rate of the reverse reaction

Question 20

Which of the following is true about van der Waals interactions?

Accepted Answer

They are weak attractions between molecules due to temporary fluctuations in electron distribution

The Chemical Context of Life: Study Notes (General Biology, Chapter 2)

Guida di studio - Domande di pratica