Chemistry revision. Unit C3

What is meant by the term ‘Valency’?

Valency is defined as the combining power of an element.

GIve the 3 elements with valency 0 and its symbol

• Argon, Ar

• Helium, He

• Neon, Ne

Give the 8 elements with valency 1 And its symbol

• Bromine, Br

• Chlorine, Cl

• Iodine, I

• Fluorine, F

• Hydrogen, H

• Pottasium, K

• Sodium, Na

• Silver, Ag

Give the 5 elements with the valency 2 and its symbol

• Calcium, Ca

• Magnesium, Mg

• Barium, Ba

• Oxygen, O

• Zinc, Zn

Give the element with valency 1 or 3 And its symbol

Gold, Au

Give the element with valency 2 or 3 And its symbol

Iron, Fe

Give the elements with the valency 2 or 4 and its symbol

• Carbon, C

• Tin, Sn

• Lead, Pb

Give the elements with valency 3 and their symbols

• Aluminium, Al

• Nitrogen, N

Give the 2 elements with valency 1 or 2 and their symbols

• Copper, Cu

• Mercury, Hg

Give the element with valency 2,4 or 6 and its symbol

• Sulfur,

GIve the element with valency 3 or 5 and its symbol

Phosphorus, P

What is meant by the term ‘Symbol’?

A symbol is a short-hand way to reprensent an element.

What is meant by the term ‘Formulae’?

Formulae is used to represent molecules compounds and radicals

What is meant by the term ‘Molecule’?

A molecule consists of two or more atoms chemically joined together

What is meant by the term of ‘diatomic molecules’?

Diatomic molecules consists of 2 atoms of non-mental chemically joined together.

Give the 7 diatomics molecules

• Hydrogen, h2

• Nitrogen, n2

• Fluorine

• Oxygen

• Iodine

• Chlorine

• Bromine

What is meant by the term ‘Radicals’?

Radicals is a group of atoms chemically joined together, having a formulae and a valency.

Give the 5 radicals

• Hydroxide, OH, valency one

• Nitrate, NO3, valnecy 1

• Ammonium, NH4, valancy 1

• Carbonate, CO3, valency 2

• Sulfate, SO4, valency 2