Chemistry Flashcards
What are isotopes?
Isotopes are atoms that have the same number of protons, but a different number of neutrons. and a different mass
what is a Chemical Reaction?
Chemical reactions occur when the electrons in an atom are traded or shared to form new compounds
What are valence electrons?
they are the atoms on the outer shell and The valence electrons are transferred from one atom to another to form ions.
What are ions
Ions are formed when atoms gain or lose electrons. Positive ions (cations) are formed when atoms lose electrons. Negative ions (anions) are formed when elements gain electrons.
Exothermic reaction?
These occur when the energy stored in the products is less than the energy stored in the reactants.
The extra energy is released to the surroundings as either heat or light.
Endothermic reaction?
These occur when the amount of energy stored in the products is greater than the amount stored in the reactants.
In order for the products to be produced energy needs to be absorbed from the environment
Hydrocarbons
Hydrocarbons are fuels that we can burn to produce a large amount of energy
They are substances that only contain carbon and hydrogen bonds. These are high energy bonds.
Acids
Acids are corrosive, they eat away at solid substances
They have a sour taste
Less than 7 are acids on PH scale
turns litmus paper red
Bases
Have a slippery, soapy feel
Have a bitter taste
more than 7 are bases on PH scale
turns litmus paper blue
Neutralisation
This is when an acid and a bases react with each other
ACID + BASE → SALT + WATER
Acids and Metals
When an acid and a metal react, hydrogen gas is produced
ACID + METAL → SALT + HYDROGEN GAS
Acids and carbonates
When acids are added to carbonates or hydrogen carbonates they produce carbon dioxide in solution.
ACID + CARBONATE SALT + WATER + CARBON DIOXIDE
factors affecting reaction rate
Agitation
Catalyst
Temperature
Surface area
Decomposition
one substance splits into two
Precipitation
two products leave a substance behing (insoulable)
