An atom’s first 2 energy levels are filled and there are 2 electrons in the third energy level. It’s atomic number is:

An atom of U-238 contains:

Give the chemical formula for the following compounds:  (2 marks each) a) magnesium oxide      b) zinc sulphate   c) iron(II) phosphate   d) calcium hydroxide   e) sodium bicarbonate

An isotope has:

Two elements are mixed, and react with evolution of heat and light. The reaction may be classified as:

The statement that best defines the alkali metals is:

The burning of natural gas is a change that is:

Balance each of the following equations:  (3 marks each) a) H2SO4 + Al(OH)3 → Al2(SO4)3 + H2O b) Ca3P2 + H2O → PH3 + Ca(OH)2 c) C3H7OH + O2 → CO2 + H2O d) Cl2 + CrBr3 → Br2 + CrCl3

HCl(aq) represents liquid hydrochloric acid.

Consider the graph of the quadratic function . Determine the intervals where the function is increasing and decreasing.