1.It is the one of the regions in an atom where electrons are found.
A. nucleus
B. shell
C. rings
D. orbitals

2.Group II atoms
A. gain 1 electron
B. gain 2 electrons
C. lose 1 electron
D. lose 2 electrons

3.It is used in preserving organic materials like an animal specimen and embalming human cadavers.
A. Acetone
B. Formalin
C. Calcium carbide
D. Alcohol

4.It is used as antiseptic or disinfectant, component of liquor, cleaning agent and fuel for portable stove or other types of burners.
A. Acetone
B. Formalin
C. Calcium carbide
D. Alcohol

5.How much is the molar mass of NaOH?
A. 42 g/mol
B. 40 g/mol
C. 50 g/mol
D. 52 g/mol

6.What is the percentage of oxygen in carbon dioxide (CO^)?
A. 27.3%
B. 72.7%
C. 30%
D. 70%​