Chemistry Questions

What is formed when helium atom loses one electron?

Which  of  the  following  substances  cause temporary hardness in water?

1. Mg(HCO3)2

2. Ca(HCO3)2

3. CaCl2

4. MgSO4

Which of the following statements are CORRECT?

I. Oxides of metals are generally basic.

II. Oxides of non-metals are generally acidic.

III. Non-metals are generally electro positive.

The movement of water molecules through the plasma membrane is called ______.

Find the similarity in the following :

Carbon, Silicon, Boron, Arsenic

Generally covalently bonded molecules ______.

I. have high boiling and melting point as compare to ionically bonded molecules

II. poor conductors of electricity

III. have weak intermolecular force

In a combination reaction there can be ______.

I. two or more than two reactants

II. two or more than two products

III. only one product

___ is the number of shells for elements of the 3rd period.