Which element has both metallic and nonmetallic properties?

(1) Rb (3) Si

(2) Rn (4) Sr

How many unshared pairs of electrons are there in a molecule of HCl?

A substance contains 35.0 g nitrogen, 5.05 g hydrogen, and 60.0 g of oxygen. how many grams of hydrogen are there in a 153-g sample of this substance

A student collected nitrogen by displacing water in a graduated cylinder. the atmospheric pressure was 738.9 mmhg; the height of the water remaining in the cylinder was 13.2 mm; the partial pressure of the water was 18.8 mmhg.

A gas occupies 12.3 liters at a pressure of 40.0 mm Hg. What is the volume when the pressure is increased to 60.0 mm Hg?

How many barium atoms are in Ba (MnO4) 2?

Balance this equation- Na3PO4 + KOH - > NaOH + K3PO4

Carbon dioxide, or CO2, is a (n) A.) atom. B.) mixture. C.) element. D.) compound.

If the atomic number of an element is 6 and its mass number is 20, how many neutrons are in the atom's nucleus?

A chemist exploring potential fuels for use in outer space is considering using vaporized aluminum chloride as a fuel.

Dinitrogen monoxide has a structural formula of NNO and requires resonance structures in order to draw the Lewis structures of the molecule.