1.2 INTRO TO CHEMISTRY

Question 1

What are the two main types of chemical bonds?

Answer 1

Ionic and covalent

Question 2

What are valence electrons?

Answer 2

Outermost electrons important for bonding

Question 3

List the types of intermolecular forces.

Answer 3

• Hydrogen bonding
• Van der Waals

Question 4

Define matter.

Answer 4

Anything that has mass and takes up space

Question 5

What is the main component of matter?

Answer 5

Atoms

Question 6

What is the difference between mass and weight?

Answer 6

Mass is the amount of matter; weight is the force of gravity on an object

Question 7

What is a pure substance composed of only one type of atom called?

Answer 7

Element

Question 8

What is a compound?

Answer 8

Two or more elements bonded together

Question 9

What are mixtures?

Answer 9

Two or more elements or compounds mixed together but not bonded

Question 10

Who proposed the atomic theory that states all matter is composed of atoms?

Answer 10

John Dalton

Question 11

What is the atomic number?

Answer 11

The number of protons in an atom

Question 12

What is an isotope?

Answer 12

Atoms of the same element with different numbers of neutrons

Question 13

What is a cation?

Answer 13

A positively charged ion formed by losing electrons

Question 14

What is an anion?

Answer 14

A negatively charged ion formed by gaining electrons

Question 15

What does the octet rule state?

Answer 15

Main group atoms prefer to have 8 valence electrons

Question 16

What is the primary focus of chemistry?

Answer 16

Electrons

Question 17

What are the two types of covalent bonds?

Answer 17

• Polar
• Non-polar

Question 18

Describe an ionic bond.

Answer 18

Involves the transfer of electrons from one atom to another

Question 19

What is a chemical formula?

Answer 19

Indicates the elements present in a compound and the relative number of atoms

Question 20

What is the significance of the periodic table?

Answer 20

Lists all known elements according to their atomic numbers and chemical behavior

Question 21

What is the mass number?

Answer 21

The sum of protons and neutrons in an atom

Question 22

True or False: Electrons are heavier than protons and neutrons.

Answer 22

False

Question 23

Fill in the blank: A _______ is formed when a neutral atom gains or loses electrons.

Answer 23

Ion

Question 24

What does the term ‘nuclear radiation’ refer to?

Answer 24

Energetic subatomic particles emitted from unstable nuclei

Question 25

What is the role of valence electrons in chemical bonding?

Answer 25

They can be shared or exchanged more easily

Question 26

What type of bond involves the sharing of electrons?

Answer 26

Covalent bond

Question 27

What happens to sodium (Na) when it forms an ionic bond with chlorine (Cl)?

Answer 27

Na loses an electron to become Na+; Cl gains an electron to become Cl-

Question 28

What is the formula for water?

Answer 28

H2O

Question 29

What is the relationship between protons, neutrons, and electrons in a neutral atom?

Answer 29

The number of protons equals the number of electrons

Question 30

What are the four elements proposed by Empedocles?

Answer 30

* Earth * Air * Fire * Water

Question 31

What is the primary characteristic of noble gases?

Answer 31

They are unreactive and do not gain or lose electrons

Question 32

What does it mean for a compound to have a constant composition?

Answer 32

It contains the same proportions of its constituent elements

Question 33

What ion does sodium become after losing an electron?

Answer 33

Na+ ## Footnote Sodium ion is formed when a sodium atom loses one electron.

Question 34

What ion does chlorine become after gaining an electron?

Answer 34

Cl– ## Footnote Chloride ion is formed when a chlorine atom gains one electron.

Question 35

What is the formula for sodium chloride?

Answer 35

NaCl ## Footnote Sodium chloride is formed from the ionic bond between sodium and chlorine.

Question 36

What type of bond is formed by the transfer of electrons?

Answer 36

Ionic bonds ## Footnote Ionic bonds involve the attraction between positively and negatively charged ions.

Question 37

What are the main types of bonds and forces in chemistry?

Answer 37

Ionic bonds, Covalent bonds (polar and non-polar), Intermolecular forces (van der Waals and Hydrogen bonding) ## Footnote These bonds and forces dictate the interactions between atoms and molecules.

Question 38

How are chemical compounds formed?

Answer 38

When atoms of different types come together in specific ratios. ## Footnote This can involve either ionic or covalent bonding.

Question 39

What characterizes ionic compounds?

Answer 39

The full transfer of electrons from one species to another. ## Footnote This results in the formation of positively and negatively charged ions.

Question 40

What characterizes covalent compounds?

Answer 40

Atoms form a bond by sharing electrons. ## Footnote This sharing can be equal or unequal, leading to polar or nonpolar covalent bonds.

Question 41

Define a covalent bond.

Answer 41

When two atoms share electrons in their outer shell. ## Footnote This can lead to different types of covalent bonds based on electron sharing.

Question 42

What is an example of a nonpolar covalent bond?

Answer 42

Methane (CH4) ## Footnote In methane, electrons are shared equally between carbon and hydrogen atoms.

Question 43

What is an example of a polar covalent bond?

Answer 43

Water (H2O) ## Footnote In water, oxygen pulls electrons closer, creating a slight negative charge on oxygen and a slight positive charge on hydrogen.

Question 44

What is meant by 'polarity' in chemistry?

Answer 44

The property of having poles; a separation of electric charge leading to a molecule having a negatively charged end and a positively charged end. ## Footnote Polarity affects the physical properties and reactivity of molecules.

Question 45

True or False: Nonpolar covalent bonds have symmetric electron distribution.

Answer 45

True ## Footnote In nonpolar covalent bonds, electrons are shared equally, resulting in no charge separation.

Question 46

What happens when atoms share electrons unequally?

Answer 46

The result is a polar covalent bond. ## Footnote This occurs when one atom has a higher electronegativity than the other.

Question 47

What type of bond is formed between positively and negatively charged ions?

Answer 47

Ionic bonds ## Footnote These bonds result from the electrostatic attraction between ions.

Question 48

Fill in the blank: Covalent bonds are formed when atoms share electrons to obtain a _______.

Answer 48

octet ## Footnote Atoms strive for a full outer shell of electrons, typically eight.