Year 11 Chemistry 24-25 Flashcards
What did John Dalton do?
-all elements are made up of small indivisible particles called atoms
-atoms cannot be created or destroyed
-atoms of different elements have different properties
what did j.j thompson do?
-discovered the electron
-proposed the plum pudding model
-suggested atom was neutral as it contained equal number of protons and electrons
what is the plum pudding model
negative electrons embedded into a sphere of positive charge
what did ernest rutherford do?
-proved that atoms consisted of electrons revolving around positively charged nucleus
-called the positive particles protons
what did james chadwick do?
-showed the nucleus of the atom contained two different types of particles
-neutral particles are called neutrons
-they were difficult to detect because it had no charge
what is ionic bondinf
-occurs between metals and non-metals e.g. sodium chloride
-when a metal transfers electrons to a non metal forming positive and negative ions
what’s a cation
a positive ions
what’s an anion
a negative ion
what are the physical properties of ionic compounds
-high melting and boiling point
-ionic substances are soluble in water
-electrical conductivity
what is covalent bonding
-occurs between non-metal atoms only
-involves sharing pairs of electrons
what does covalent bonding look like?
(H ( ) X O ( ) Cl)
what is the relative mass of a proton, neutron and electron
p- 1
n- 1
e- 1/1840
what is the relative charge of a proton, neutron and electron
p - +1
n - 0
e = -1
what is the proton and neutron found
nucleus
where is the electrons found
the shell
