unit 1

Question 1

What is matter?

Answer 1

Matter is anything that occupies space and has mass.

Question 2

Define an element.

Answer 2

An element is a pure substance that cannot be created or broken down by ordinary chemical means.

Question 3

What are the four most abundant elements in the human body?

Answer 3

• Oxygen (O)
• Carbon (C)
• Hydrogen (H)
• Nitrogen (N)

Question 4

What is a molecule?

Answer 4

A molecule is formed by the combination of two or more atoms joined by chemical bonds.

Question 5

Define a compound.

Answer 5

A compound is a substance containing at least two different elements joined by chemical bonds.

Question 6

What is an inorganic compound?

Answer 6

An inorganic compound is a substance that does not contain both carbon and hydrogen.

Question 7

Provide an example of an inorganic compound.

Answer 7

Water (H2O) and hydrochloric acid (HCl).

Question 8

Define an organic compound.

Answer 8

An organic compound is a substance that contains carbon-hydrogen bonds.

Question 9

What is the significance of ATP in human cells?

Answer 9

ATP is vital for the functioning of human cells, providing energy for various biochemical processes.

Question 10

What is an atom?

Answer 10

An atom is the smallest quantity of an element that retains the unique properties of that element.

Question 11

Name the three important subatomic particles.

Answer 11

• Proton
• Neutron
• Electron

Question 12

What determines the atomic number of an element?

Answer 12

The atomic number is determined by the number of protons in the nucleus of an atom.

Question 13

How is mass number calculated?

Answer 13

Mass number is the sum of the number of protons and neutrons in an atom’s nucleus.

Question 14

What is the octet rule?

Answer 14

The octet rule states that atoms are most stable when they have eight electrons in their valence shell.

Question 15

What happens to an atom when it becomes an ion?

Answer 15

The atom gains or loses one or more electrons, resulting in a positive or negative charge.

Question 16

Define a cation.

Answer 16

A cation is a positively charged ion.

Question 17

Define an anion.

Answer 17

An anion is a negatively charged ion.

Question 18

What is an ionic bond?

Answer 18

An ionic bond is an ongoing, close association between ions of opposite charge.

Question 19

What role does water play regarding ionic bonds?

Answer 19

Water can break ionic bonds in salts to free the ions.

Question 20

What are electrolytes?

Answer 20

Electrolytes are charged ions that produce electrical activity in the body.

Question 21

Fill in the blank: An atom’s __________ shell is its outermost electron shell.

Answer 21

valence

Question 22

True or False: Electrons travel in fixed orbits around the nucleus.

Answer 22

False

Question 23

What is the behavior of electrons in an atom?

Answer 23

Electrons tend to stay within certain regions of space called electron shells.

Question 24

How many electrons can the first three electron shells hold?

Answer 24

• First shell: 2 electrons
• Second shell: 8 electrons
• Third shell: 18 electrons

Question 25

What is a common feature of elements in the periodic table?

Answer 25

Elements are arranged in order of their atomic number and identify their chemical symbol and mass number.

Question 26

How do atoms achieve a full valence shell?

Answer 26

Atoms will give up, gain, or share electrons with other atoms.

Question 27

What does the atomic number identify besides the element?

Answer 27

The atomic number usually identifies the number of electrons in a neutral atom.

Question 28

What are substances formed through ionic bonding referred to as?

Answer 28

Compounds

Question 29

Why is water considered essential for life?

Answer 29

It breaks ionic bonds in salts to free ions

Question 30

What do dissolved ions produce within the body?

Answer 30

Electrical charges

Question 31

What are electrolytes?

Answer 31

Charged ions that produce electrical activity in the body

Question 32

What is an ionic bond?

Answer 32

A bond of attraction formed between a cation and an anion

Question 33

How does sodium form an ionic bond with chlorine?

Answer 33

Sodium donates an electron to chlorine

Question 34

What are crystals in the context of ionic bonding?

Answer 34

Large groupings of sodium and chloride ions

Question 35

What characterizes covalent bonds?

Answer 35

Atoms share electrons in a mutually stabilizing relationship

Question 36

What is a single covalent bond?

Answer 36

A bond where a single electron pair is shared between two atoms

Question 37

What is a double covalent bond?

Answer 37

A bond where two pairs of electrons are shared between two atoms

Question 38

What defines nonpolar covalent bonds?

Answer 38

Electrons are shared equally and there is no charge imbalance

Question 39

What is a polar covalent bond?

Answer 39

A bond where electrons are shared unequally, creating regions with partial charges

Question 40

What is the most familiar example of a polar molecule?

Answer 40

Water

Question 41

What is the shape of a water molecule due to its dipole?

Answer 41

Triangular tent shape

Question 42

What is a hydrogen bond?

Answer 42

An attraction between a slightly positive hydrogen atom and a slightly negative atom

Question 43

What is the most common example of hydrogen bonding in nature?

Answer 43

Between molecules of water

Question 44

What happens when sodium chloride dissolves in water?

Answer 44

Dipole-ion bonds form, allowing Na+ and Cl– to separate

Question 45

Why does oil form a distinct bead in water?

Answer 45

Water molecules repel nonpolar oil

Question 46

What unusual property does water have regarding density?

Answer 46

Ice is less dense than liquid water

Question 47

What is the boiling point of water?

Answer 47

100°C

Question 48

What affects the specific heat capacity of water?

Answer 48

Hydrogen bonding

Question 49

Fill in the blank: Water has an unusually high boiling point of ______.

Answer 49

100°C

Question 50

True or False: Covalent bonds are typically broken apart in water.

Answer 50

False