the valencies of metals X, Y and Z are 1,2 and 3 respectively. What are the formulae of their:. a)hydroxides? b)sulphates? c) carbonates? d) hydrogen carbonates? e)nitrates? f)phosphates?​

The reaction q+r2=r2q is found to be first order in r2 and

In the reaction between a crushed antacid tablet and vinegar what gas is emitted

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.