science ch 4 vocab

Question 1

An atom’s central region which is made up of protons and neutrons.

Answer 1

Nucleus

Question 2

A subatomic particle that has a positive charge and that is found in the nucleus of an atom.

Answer 2

Proton

Question 3

A subatomic particle that has no charge and that is found in the nucleus of an atom.

Answer 3

Neutron

Question 4

A subatomic particle that has a negative charge.

Answer 4

Electron

Question 5

An electron that is found in the outer-most shell of an atom and that determines the atom’s chemical properties.

Answer 5

Valence electron

Question 6

The law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements.

Answer 6

Periodic law

Question 7

A horizontal row of elements in the periodic table.

Answer 7

Period

Question 8

A vertical column of elements in the periodic table.

Answer 8

Group

Question 9

An atom or group of atoms that has lost or gained one or more electrons and has a negative or positive charge.

Answer 9

Ion

Question 10

The number of protons in the nucleaus of an atom.

Answer 10

Atomic number

Question 11

The sum of the numbers of protons and neutrons in the nucleus of an atom.

Answer 11

Mass number

Question 12

An atom that has the same number of protons as other atoms of the same element do but that has a different number of neutrons.

Answer 12

Isotope

Question 13

A unit of mass that describes the mass of an atom or molecule; it is exactly one-twelfth of the mass of a carbon atom with mass number 12.

Answer 13

Atomic mass unit (amu)

Question 14

The weighted average of the masses of all naturally occurring isotopes of an element.

Answer 14

Average atomic mass

Question 15

Average atomic mass

Answer 15

The weighted average of the masses of all naturally occurring isotopes of an element.

Question 16

An element that is shiny and conducts heat and electricity well.

Answer 16

Metal

Question 17

Nonmetal

Answer 17

An element that conducts heat and electricity poorly.

Question 18

An element or compound that conducts electric current better than an insulator but not as well as a conductor does.

Answer 18

Semiconductor

Question 19

Alkali metal

Answer 19

One of the elements of Group 1 of the periodic table.

Question 20

Alkaline-earth metal

Answer 20

One of the elements of Group 2 of the periodic table.

Question 21

One of the elements of Groups 3-12 of the periodic table.

Answer 21

Transition metal

Question 22

One of the elements of Group 17 of the periodic table.

Answer 22

Halogen

Question 23

An unreactive element of Group 18 of the periodic table.

Answer 23

Noble gas

Question 24

The SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in 12 g of carbon-12.

Answer 24

Mole

Question 25

Equals 6.022 x 10^23 / mol; the number of particles in 1 mol.

Answer 25

Avogadro’s constant

Question 26

The mass in grams of 1 mol of a substance.

Answer 26

Molar mass

Question 27

A ratio that is derived from the equality of two different units and that can be used to convert from one unit to another.

Answer 27

Conversion factor