Chemical reactions
The substances reacting together in a chemical reactions are called
The reactants
What does pH mean?
Hydrogen potential
The periodic table is organised in columns and rows. These are called
Groups and periods
positive
Matter is
something that occupies space and has weight
How many types of chemical reactions can we identify?
8
What is a pH indicator?
A substance that changes colour depending on the acidity of it environment
Which group of elements is un-reactive?
Noble gases
The sum of protons and neutrons in the nucleus is
Atomic mass
Burning wood or a rooting banana are examples of _____ change
Chemical
The total mass of the reagents in a chemical reaction is equal to the mass of the products. This is the
Principle of conservation of mass
If you add water to a strong acid, what happens to its pH?
Gets closer to neutral
Which group includes nickel, iron and copper?
Transition metals
An element is
Homogenous mixtures can be defined as
a mixtures with the same properties in all its parts
What does a combustion reaction require to happen?
Oxygen and energy
coffee, lemon juice, water, baking soda
Acids: coffee and lemon juice
Bases: baking soda
Neutral: water
Give the chemical symbol of the following elements:
Chlorine, calcium, oxygen, iron, mercury, hydrogen, copper, sodium
Cl, Ca, O, Fe, Hg, H, Cu, Na
Ions are atoms
that lost or gain an electron
A colloid is
A type of mixture in which very small particles of the solute are disperse in a solvent (fog or milk)
Look at this reactions and classify them:
2HgO ➜ 2Hg + O2
HCl + NaOH ➜ NaCl + H2O
Fe + S ➜ FeS
decomposition
doble exchange/neutralisation
Synthesis
Which acid and base can form table salt? (give formula and name)
Hydrochloric acid HCl and Sodium hydroxide NaOH
Elements with an atomic number higher than ____ cannot be found in nature
92
Translate these to their chemical formulas
a diatomic molecule of oxygen
two atoms of iron
one atom of hydrogen
one molecule of sodium chlorine
O2
2Fe
H
NaCl
Calculate the mass of a solution made of 800g of solvent and 30 g of solute
830g