C3 atoms, elements and compounds Flashcards
Element
A substance that contains only one type of atom and cannot be broken down into anything simpler by chemical means
Compound
Two or more different elements chemically bonded together
Chemical change
When two or more elements combine together to form a new substance
How to know when a chemical change has taken place
- One or more new substances are formed
- Energy is taken in or given out
- The change is usually difficult to reverse
Physical change
If no new chemical substances are formed and the change is squally easy to reverse
Mixture
Contains more than one substance (just mix together and not chemically combined)
Solution
Solute + solvent = solution
Solvent
A substance which is used to dissolve the solute
Solute
A substance that dissolves in the solvent
Solubility
The ability to be dissolved
Soluble
Capable of being dissolved
Insoluble
Incapable of being dissolved
Concentration
A concentrated solution is a solution that contains a large amount of solid relative to the amount that could dissolve
Nucleon no. (mass no.)
The total number of protons and neutrons in the nucleus of an atom
Isotopes
Atoms of the same element which have the same proton number but a different nuclear number
Proton no. (atomic no.)
The number of protons in the nucleus of an atom
Proton charge
+1
Electron charge
-1
Neutron charge
0
Proton relative mass
1
Neutron relative mass
1
Electron mass
1/840 or negligible
Ionic bonding
Bonding between a metal and a non-metal atom where metal atoms need to lose electrons and non-metal atoms need to gain electrons
What happens during ionic bonding?
- The electrons are transferred from the metal to the non-metal atom
- Metal atoms lose electrons to form positive electrons while non-metal atoms gain electrons to form negative ions
- The two ions have opposite charges so they attract one another
