Chapter 4 Vocabulary

Question 0

Dalton’s atomic theory

Answer 0

1. All elements are composed of tiny indivisible particles called atoms.
2. Atoms of the same element are identical. The atoms of any one element are different from those of any other element.
3. Atoms of different elements can physically mix together or can chemically combine in simple whole-number ratios to form compounds.
4. Chemical reactions occur when atoms are separated, joined, or rearranged. Atoms of 1 element, however, are never changed into atoms of another element as a result of a chemical reaction

Question 1

Atom

Answer 1

The smallest particle of an element the retains its identity in a chemical reaction

Question 2

Electrons

Answer 2

Negatively charged subatomic particles with relative mass of 1/1840

Question 3

Protons

Answer 3

Positively charged subatomic particles with relative mass of 1

Question 4

Neutrons

Answer 4

Subatomic particles with no charge but with a mass nearly equal to that of a proton

Question 5

Nucleus

Answer 5

The tiny central core of an atom and is composed of protons and neutrons

Question 6

Atomic number

Answer 6

The number of protons in the nucleus of an atom of that element

Question 7

Mass number

Answer 7

Total number of protons and neutrons in an atom

Question 8

Isotopes

Answer 8

Atoms that have the same number of protons but different numbers of neutrons

Question 9

Atomic mass unit (amu)

Answer 9

Defined as one twelfth the mass of a carbon-12 atom

Question 10

Atomic mass

Answer 10

A weighted average mass of the atoms in a naturally occurring sample of the element

Question 11

Period

Answer 11

Each horizontal row of the periodic table

Question 12

Group

Answer 12

Each vertical column of the periodic table