Ionization energy increases across the period in the periodic table because

Which of the following properties indicate that an element is a metal. It

I. reacts with oxygen to form an acidic oxide
II. forms ionic chlorides
III. has variable oxidation states
IV. displaces hydrogen from dilute HCl

The electron configuration of carbon atom in its excited state is

An oxide has the following properties. It

I. is a white powder
II. reacts with HCI.
III. reacts with NaOH
IV. is insoluble in water
The oxide is

Which of the following statements about atoms of a metal is correct? They