chem1

Question 1

What is the basic unit of matter?

Answer 1

The atom.

Question 2

What are the three main subatomic particles in an atom?

Answer 2

Protons, neutrons, and electrons.

Question 3

What charge do protons carry?

Answer 3

Positive charge.

Question 4

What charge do electrons carry?

Answer 4

Negative charge.

Question 5

What is the charge of neutrons?

Answer 5

Neutral (no charge).

Question 6

Where are protons and neutrons located in an atom?

Answer 6

In the nucleus.

Question 7

Where are electrons located in an atom?

Answer 7

In electron shells around the nucleus.

Question 8

What is an atomic number?

Answer 8

The number of protons in the nucleus of an atom.

Question 9

What does the mass number represent?

Answer 9

The total number of protons and neutrons in an atom.

Question 10

What are isotopes?

Answer 10

Atoms of the same element with different numbers of neutrons.

Question 11

What is a covalent bond?

Answer 11

A chemical bond formed by the sharing of electrons between atoms.

Question 12

True or False: Covalent bonds can only form between nonmetals.

Answer 12

True.

Question 13

What is an ionic bond?

Answer 13

A chemical bond formed through the transfer of electrons from one atom to another.

Question 14

Which type of elements typically form ionic bonds?

Answer 14

Metals and nonmetals.

Question 15

What is a metallic bond?

Answer 15

A bond formed by the attraction between metal atoms and the surrounding sea of electrons.

Question 16

What is the periodic table?

Answer 16

A tabular arrangement of elements based on their atomic number, electron configuration, and recurring chemical properties.

Question 17

What does the group number in the periodic table indicate?

Answer 17

The number of valence electrons in an element.

Question 18

What does the period number in the periodic table indicate?

Answer 18

The number of electron shells in an atom.

Question 19

What are alkali metals?

Answer 19

Group 1 elements that are highly reactive and have one valence electron.

Question 20

What are noble gases?

Answer 20

Group 18 elements that are inert and have a full valence shell.

Question 21

What is electronegativity?

Answer 21

A measure of an atom’s ability to attract and hold onto electrons.

Question 22

What type of bond is formed when the electronegativity difference between two atoms is large?

Answer 22

Ionic bond.

Question 23

What type of bond is formed when the electronegativity difference is small?

Answer 23

Covalent bond.

Question 24

Fill in the blank: The octet rule states that atoms tend to bond in such a way that they have ____ electrons in their outer shell.

Answer 24

eight.

Question 25

What is a polar covalent bond?

Answer 25

A covalent bond in which electrons are shared unequally between atoms.

Question 26

What is a nonpolar covalent bond?

Answer 26

A covalent bond in which electrons are shared equally between atoms.

Question 27

What is a chemical formula?

Answer 27

A representation of a substance using symbols for its constituent elements.

Question 28

What is the formula for water?

Answer 28

H2O.

Question 29

What are metalloids?

Answer 29

Elements that have properties of both metals and nonmetals.

Question 30

What is the role of valence electrons in chemical bonding?

Answer 30

They are involved in the formation of bonds between atoms.

Question 31

What is a molecule?

Answer 31

A group of two or more atoms bonded together.

Question 32

What is an ion?

Answer 32

An atom or molecule that has a net electric charge due to the loss or gain of one or more electrons.

Question 33

Fill in the blank: The process of gaining electrons to form a negative ion is called _____.

Answer 33

reduction.

Question 34

What is the difference between a cation and an anion?

Answer 34

A cation is a positively charged ion, while an anion is a negatively charged ion.

Question 35

What is a crystal lattice?

Answer 35

A three-dimensional arrangement of ions in a crystalline solid.

Question 36

What property of metals allows them to conduct electricity?

Answer 36

The presence of free-moving electrons (sea of electrons).

Question 37

True or False: Ionic compounds are usually soluble in water.

Answer 37

True.

Question 38

What is the difference between an ionic compound and a covalent compound?

Answer 38

Ionic compounds are formed by the transfer of electrons, while covalent compounds are formed by the sharing of electrons.

Question 39

What is the significance of the periodic trends in atomic radius?

Answer 39

Atomic radius decreases across a period and increases down a group.

Question 40

What is the significance of periodic trends in ionization energy?

Answer 40

Ionization energy generally increases across a period and decreases down a group.

Question 41

What is the significance of periodic trends in electronegativity?

Answer 41

Electronegativity generally increases across a period and decreases down a group.

Question 42

What is a compound?

Answer 42

A substance formed when two or more different elements bond together.

Question 43

What is a polyatomic ion?

Answer 43

An ion composed of two or more atoms bonded together that carries a charge.

Question 44

What is the formula for sodium chloride?

Answer 44

NaCl.

Question 45

What are the two main types of chemical bonds?

Answer 45

Ionic bonds and covalent bonds.

Question 46

What is the principle behind the formation of metallic bonds?

Answer 46

The attraction between positively charged metal ions and the delocalized electrons surrounding them.

Question 47

What is a diatomic molecule?

Answer 47

A molecule composed of two atoms, which may be of the same or different elements.