Science Chapter 3 Vocab

Question 0

Electrons

Answer 0

A tiny, negatively charged particle that moves around the outside of the nucleus of an atom.

Question 1

Atom

Answer 1

Smallest particle that can still be considered and element

Question 2

Nucleus

Answer 2

The central core of an atom which contains protons and neutrons

Question 3

Protons

Answer 3

Small, positively charged particles that are found in the nucleus of an atom.

Question 4

Energy level

Answer 4

A region of an atom in which electrons of the same energy are likely to be found.

Question 5

Neutron

Answer 5

A small particle in the nucleus of the atom, with no electrical charge.

Question 6

Atomic number

Answer 6

The number of protons in the nucleus of an atom.

Question 7

Isotopes

Answer 7

An atom with the same number of protons and a different number of neutrons from other atoms of the same element.

Question 8

Mass number

Answer 8

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

Question 9

Atomic mass

Answer 9

The average mass of all the isotopes of an element.

Question 10

Periodic Table

Answer 10

An arrangement of the elements showing the repeating pattern of their properties.

Question 11

Chemical Symbol

Answer 11

A one- or two-letter representation of an element.

Question 12

Periods

Answer 12

1. A horizontal row of elements in the periodic table

Question 13

Metals

Answer 13

A class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity.

Question 14

Group

Answer 14

Elements in the same vertical column of the periodic table; also called family.

Question 15

Luster

Answer 15

The way a mineral reflects light from its surface.

Question 16

Malleable

Answer 16

A term used to describe material that can be hammered or rolled into flat sheets.

Question 17

Ductile

Answer 17

A term used to describe a material that can be pulled out into a long wire.

Question 18

Thermal Conductivity

Answer 18

The ability of an object to transfer heat.

Question 19

Electrical Conductivity

Answer 19

The ability of an object to carry electric current.

Question 20

Reactivity

Answer 20

The ease and speed with which an element combines, or reacts, with other elements and compounds.

Question 21

Corrosion

Answer 21

The gradual wearing away of a metal element due to a chemical reaction.

Question 22

Alkali Metals

Answer 22

An element in Group 1 of the periodic table.

Question 23

Alkaline Earth Metals

Answer 23

An element in Group 2 of the periodic table.

Question 24

Transition Metals

Answer 24

One of the elements in Groups 3 through 12 of the periodic table.

Question 25

Nonmetal

Answer 25

An element that lacks most of the properties of a metal.

Question 26

Diatomic Molecule

Answer 26

A molecule consisting of two atoms.

Question 27

Halogens

Answer 27

An element found in Group 17 of the periodic table.

Question 28

Noble gases

Answer 28

An element in Group 18 of the periodic table.

Question 29

Metalloid

Answer 29

An element that has some characteristics of both metals and nonmetals.

Question 30

Semiconductors

Answer 30

A substance that can conduct electric current under some conditions.

Question 31

Radioactive decay

Answer 31

The process in which the nuclei of radioactive elements break down, releasing fast-moving particles and energy.

Question 32

Nuclear reaction

Answer 32

A reaction involving the particles in the nucleus of an atom that can change one element into another element.

Question 33

Radioactivity

Answer 33

The spontaneous emission of radiation by an unstable atomic nucleus.

Question 34

Alpha particle

Answer 34

A particle given off during radioactive decay that consists of two protons and two neutrons.

Question 35

Beta particle

Answer 35

A fast-moving electron that is given off as nuclear radiation.

Question 36

Gamma rays

Answer 36

Electromagnetic waves with the shortest wavelengths and highest frequencies.

Question 37

Half-life

Answer 37

The time it takes for half of the atoms of a radioactive element to decay.

Question 38

Tracer

Answer 38

A radioactive isotope that can be followed through the steps of a chemical reaction or industrial process.