Periodic Tabke

Question 1

What are atoms?

Answer 1

Atoms are the basic building blocks of all materials.

Question 2

Element

Answer 2

An element is a substance made up of only one type of atom.

Question 3

Oxygen

Answer 3

O

Question 4

Carbon

Answer 4

C

Question 5

Potassium

Answer 5

K

Question 6

Nitrogen

Answer 6

N

Question 7

Monlecule

Answer 7

A molecule is formed when two or more atoms join (bond) together chemically.

Question 8

Compounds

Answer 8

When a molecule is made up of two or more different types of elements chemically combined, we call it a compound.

Question 9

Atomic and mass numbers

Answer 9

Atoms of different elements differ from each other by the number of protons, neutrons and electrons they have.

Question 10

The modern periodic table

Answer 10

Vertical columns, called groups, in which the elements with similar physical and chemical properties (behaviours) are grouped together
• Horizontal rows, called periods, which are in order of increasing proton number.

Question 11

Group 1 - the alkali metals

Answer 11

All the alkali metals have one electron in their outer shell. The atoms want’ to get rid of this loose electron. As a result, the alkali metals are very reactive and behave similarly. Elements in this group include:
• Lithium (Li)
• Sodium (Na)
• Potassium (K).

Question 12

Group 2 - the alkaline earth metals

Answer 12

Elements in this group include:
Beryllium (Be)
Magnesium (Mg)
• Calcium (Ca).
All elements in this group have two electrons in their outer shell.
Group 2 elements are not as reactive as group 1 elements.

Question 13

Group 7 - the halogens

Answer 13

The elements in group 7 have seven electrons in their atom’s outer shell. (The word ‘halogen’ also contains seven letters!) Elements in this group include:
• Fluorine (F), in the form of compounds such as sodium fluoride, which is sometimes added to water to strengthen enamel in our teeth.
• Chlorine (CI), which is sometimes added to water to kill bacteria.
Elements in this group are ‘trying’ to gain an electron because they want a full outer shell.

Question 14

Group 8 (group 0) - the noble gases

Answer 14

The elements in group 8 are all gases and have full outer shells of electrons in their atoms. As a result, the noble gases are unreactive and thus very stable. Members of the noble gases include:
• Helium (He)
• Neon (Ne)
• Argon (Ar), which is used in filament lamps (light bulbs).

Question 15

Electron shell rules

Answer 15

• Electrons are found in shells, or orbits.
• The shells nearest the nucleus are filled first.
• The first shell can hold up to two electrons.
• The second and third shells can hold up to eight electrons each.
• Atoms that have a full outer shell of electrons are stable and do not react.
• In most atoms the outer shell is not full, and this makes them more likely to react.

Question 16

What are ions?

Answer 16

All atoms would ‘like’ full outer shells and will either lose or gain electrons in order to achieve this.
When atoms lose or gain electrons they become charged particles and are called ions. The elements that readily form ions make up groups 1, 2, 6 and 7.

Question 17

How are chemical bonds formed?

Answer 17

A compound forms when two different elements chemically combine.

Question 18

Covalent bonding

Answer 18

Covalent bonding produces a compound formed from non-metals in which each atom shares electrons with another atom.

Question 19

Group names

Answer 19

The periodic table has four named groups. They are:
• Group 1 - the alkali metals
• Group 2 - the alkaline earth metals
• Group 7 - the halogens
• Group 8 - the noble gases.

Question 20

lonic bonding

Answer 20

lonic bonding produces a compound that is formed from a metal and a non-metal and is made up of ions. This occurs when one atom loses electrons and another atom gains electrons.