Key Terms - Atomic Theory

Question 1

What is the Mass Number?

Answer 1

The mass number is the number found in the top corner of the symbol. It is the total number of proton’s and neutron’s.

Question 2

What is the Atomic Number?

Answer 2

The atomic number is the atom is the number of protons it contains. All the atoms of a particular element have the same atomic number.

Question 3

Atoms

Answer 3

An atom is the smallest part of an element that can exist - Ions are atoms that develop a charge. Radius of atom: 0.1nm (1 x 10^-10m)

Question 4

Elements

Answer 4

An element is a pure substance made of only one type of element and it cannot be broken down into simple elements by chemical processes.

Question 5

Compound

Answer 5

A compound is a substance that contains two or more elements that are chemically bonded/combined.

Question 6

Molecules

Answer 6

A molecule is a group of two or more atoms joined together by covalent bonds.

Question 7

Proton

Answer 7

A proton is a subatomic particles which is always contained in the nucleus with neutrons. The have a positive charge, with a relative mass of 1 and a relative charge of 1.

Question 8

Neutron

Answer 8

A subatomic particle that forms the central nucleus of almost all atoms along with protons. Neutrons have a no charge with a relative mass of 1 and a relative charge of 0

Question 9

Electron

Answer 9

Subatomic particle, with a negative charge, relative mass of 1/2000 (very small) and a relative charge of -1. Electrons are attached to the shell/shells or energy levels, which orbit around the centre nucleus. Electrons can be shared and are responsible for chemical reactions.

Question 10

Nucleus

Answer 10

The nucleus consists of protons and neutrons (subatomic particles). A nucleus is located at the centre of an atom and is surrounded by energy levels. When a nucleus is messed with, a nuclear reaction is caused due to it being unbalanced. The radius of the nucleus is 1/10,000

Question 11

Periodic Table

Answer 11

The periodic table is the chart that shows all the elements arranged in order of increasing atomic number. There are more than 100 elements inside it and all of them are different (special categories), for eg: metalloids, noble gases and halogens.

Question 12

Groups (Periodic Table)

Answer 12

The vertical columns on the periodic table are called groups. The groups determine how many electrons are located on the valent shell (outer shell).

Question 13

Periods (Periodic Table)

Answer 13

The horizontal rows on the periodic table are called periods.

Question 14

Ions

Answer 14

Ions are atoms that develop a charge via the process of a chemical reaction.

Question 15

Cations

Answer 15

Cations are ioms with a positive charge and a result of a chemical reaction with metal

Question 16

Anions

Answer 16

Anions are ions with a negative charge as a result of reduction.