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____________ reaction happens when energy is released to the surroundings and the temperature of the surroundings increases.
Exothermic
_____ reaction happens when energy is absorbed from the surroundings and the temperature of the surroundings decreases
Endothermic
When an exothermic reaction takes place, the reaction mixture gives out heat because more energy is ____ when new bonds are formed than is taken in when existing bonds in the reactants are broken.
released
Energy change in a chemical reaction is represented by the symbol...
ΔH (enthalpy change)
ΔH is negative for what type of reactions?
exothermic reactions
At __________, the rate of the forward and reverse reaction are the same. the rate of the forward and reverse reaction are the same.
equilibrium
A reaction which will proceed in both forwards and backwards directions is called a _____________.
reversible reaction
What gas is given off when group I elements react with water?
hydrogen gas
The reactivity of group I elements ______ down the group.
increases
When a group 1 element reacts with water, a hydroxide is formed. What colour could Universal Indicator turn in this solution?
blue or purple (alkaline)
What is the transition metal used as a catalyst(to convert carbon monoxide to carbon dioxide) in the car exhaust?
platinum
The minimum amount of energy required by particles to react is called the _________.
activation energy
What is the reaction in which an acid reacts with a base or alkali to form a salt and water called?
neutralisation
As you go down group 7, from fluorine to astatine, what happens to the reactivity of the elements?
reactivity decreases
What happens to the density of group 1 metals as you go down the group?
increases
chlorine + potassium bromide ==> potassium chloride + bromine What is this reaction called?
Displacement reaction
