Q: Which formula correctly represents the calculation of mass number for an atom?

$$\text{Mass number} = \text{Number of protons} + \text{Number of neutrons}$$

Q: What is the correct formula for calculating atomic mass (atomic weight) based on isotopes?

$$\text{Atomic mass} = \text{Weighted average of mass numbers based on isotope abundance}$$

Question 1

Which element makes up the largest percentage of human body weight, and what is its primary biological function?

Accepted Answer

Oxygen; it is essential for cellular respiration and water formation.

Question 2

A patient presents with a swollen neck, as shown in the image. Which trace element deficiency is most likely responsible for this condition, and what hormone is affected?

Accepted Answer

Iodine deficiency; thyroid hormone production is affected.

Question 3

Red blood cells are unable to transport oxygen efficiently in the absence of which trace element, and what is the relevant protein involved?

Accepted Answer

Iron; hemoglobin

Question 4

Table salt (NaCl) is formed from sodium and chlorine. What type of bond holds these ions together, and what is the process called?

Accepted Answer

Ionic bond; electron transfer

Question 5

Which four elements are most abundant in living organisms and are found in DNA?

Accepted Answer

Carbon, hydrogen, oxygen, nitrogen

Question 6

Given the atomic number and mass number of helium (atomic number 2, mass number 4), how many neutrons does a helium atom have?

Accepted Answer

2 neutrons

Question 7

Which formula correctly represents the calculation of mass number for an atom?

Accepted Answer

$$	ext{Mass number} = 	ext{Number of protons} + 	ext{Number of neutrons}$$

Question 8

Hydrogen has three isotopes: 1H, 2H, and 3H. Which isotope is radioactive, and what is its mass number?

Accepted Answer

3H; mass number 3

Question 9

Carbon-14 is used in medical imaging and research. What makes it different from Carbon-12?

Accepted Answer

It has more neutrons than Carbon-12.

Question 10

Which equation represents a synthesis reaction?

Accepted Answer

$$A + B \rightarrow AB$$

Question 11

What is the main reason water is less dense as a solid (ice) than as a liquid?

Accepted Answer

Hydrogen bonds form a stable, open crystal structure in ice.

Question 12

Which property of water allows insects to walk on its surface, as shown in the image?

Accepted Answer

Surface tension due to hydrogen bonding

Question 13

What is the correct formula for calculating atomic mass (atomic weight) based on isotopes?

Accepted Answer

$$	ext{Atomic mass} = 	ext{Weighted average of mass numbers based on isotope abundance}$$

Question 14

Which type of bond is responsible for the cohesion and surface tension of water?

Accepted Answer

Hydrogen bond

Question 15

A solution has a pH of 2. Which statement best describes its properties?

Accepted Answer

It is acidic and has a high concentration of H+ ions.

Question 16

Which equation represents the formation of water from hydrogen and oxygen?

Accepted Answer

$$2H_2 + O_2$ \rightarrow 2H_2O$$

Question 17

Which element is a trace element required to prevent disease, and what is its function?

Accepted Answer

Iron; oxygen transport in blood

Question 18

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

Accepted Answer

Polar bonds share electrons unequally, resulting in partial charges; nonpolar bonds share electrons equally.

Question 19

Which equation represents an exchange reaction?

Accepted Answer

$$AB + CD \rightarrow AD + CB$$

Question 20

What is the effect of an enzyme on the activation energy of a chemical reaction?

Accepted Answer

It decreases the activation energy required.

The Chemical Basis of Life: Essential Concepts for Anatomy & Physiology

Guida di studio - Domande di pratica

Study guide - Flashcard