Structure of an Atom
What two subatomic particles are found in the nucleus of an atom?
Protons and neutrons
What does the atomic number represent?
The number of protons
What evidence shows a chemical change has occurred?
Formation of a new substance
Does an exothermic reaction release or absorb energy?
Release energy
How does increasing temperature affect reaction rate?
It increases reaction rate
What is the charge and location of an electron?
Negative charge, orbits the nucleus
What do the periods (rows) in the Periodic Table indicate about an atom?
The number of electron shells
What type of reaction occurs when burning wood?
Combustion
Give an example of an exothermic reaction.
Combustion (burning), Acid + Base
What effect does increasing concentration of reactants have on reaction rate?
Increases reaction rate
Which subatomic particle determines the atomic number?
Proton
What is valency?
The combining power of an element (electrons in outer shell)
What reaction produces a solid when two solutions are mixed?
Precipitation
What is an endothermic reaction?
Reaction that absorbs energy
Why does smaller particle size (greater surface area) speed up reactions?
More area for collisions
Which particle has no charge and nearly the same mass as a proton?
Neutron
Where are metals located on the Periodic Table?
On the left and in the centre
What reaction type describes acid reacting with a base?
Neutralisation
Compare combustion and respiration in terms of speed and energy released.
Combustion: fast, lots of energy; Respiration: slow, less energy
What is a catalyst?
Substance that speeds up a reaction without being used up
If an atom has 7 protons, 8 neutrons, and 7 electrons, what is its atomic number and mass number?
Atomic number: 7, Mass number: 15
What information is given by the mass number of an atom?
Total number of protons and neutrons
What type of reaction is metal rusting in air?
Corrosion
What can you measure to monitor a reaction’s heat change?
Temperature
Name two ways to speed up a reaction other than using a catalyst.
Increase temperature or concentration