Chemistry Flashcards
What are elements?
Pure substances made from only one atom
What are compounds?
Two or more elements chemically joined together
What is a substance made from different types of atoms that are not chemically joined together?
Mixture
What is a substance with one type of atomt called?
Element
What is a a substance with with two or more elements chemically joined together called?
Compound
What is an alloy?
An alloy is a mixture of two or more elements, one of which is always a metal
What are the four sings of a chemical reaction?
Colour change
Energy Change
Gas given off
Precipitate forms
What is a chemical reaction?
A chemical reaction is a change, which forms new substance(s)
What is a physical change?
In a physical change appearance or form changes, but no new substances are made. Many physical changes can be easily reversed
What is a chemical reaction?
A chemical equation tells you which substance we started with (the reactants) and the new substance(s) that were made in the reaction (the product)
To prepare cobalt copper, we can add cobalt chloride to potassium carbonate. Potassium chloride would also be produced. Write the equation.
Cobalt chloride = Potassium Carbonate —> Potassium Chloride + Cobalt Carbonate
Sulfuric acid —-> ? salt
Sulfate
Nitric acid —-> ? salt
Nitrate
Hydrchloric acid —-> ? salt
Chloride
What metals are used in jewellery and why?
Platinum, gold and silver because it is less reactive
