What is the average diameter of bacteria?

• 1x10^-5 m

• 1x10^-6 m

• 1x10^-7 m

• 1x10^-10 m

Where is almost the whole mass of an atom is concentrated at?

• the electron of the atom

• the orbit of the atom

• the energy of the atom

• the nucleus of the atom

How is an atom electrically neutral?

• The positive charge and the negative charge cancel each other out.

• The positive charge and the negative charge support each other out.

• The positive charge and the negative charge improve each other out.

• The positive charge and the negative charge energize each other out.

Who did an experiment that showed that the atom consists mainly of empty space?

• John Dalton

• J. J. Thomson

• Ernest Rutherford

• Niels Bohr

What is the number of neutrons in silver atom above?

• 108

• 61

• 47

• 155

What is a molecule made up?

• two or more elements physically combined

• two or more elements chemically combined

• two or more atoms physically combined

• two or more atoms chemically combined

Which one is the molecule that DOES NOT BELONG to triatomic?

• 
• 
• 
• 

How many electrons are there in the atom model above?

• 34

• 35

• 36

• 37

Carbon : Gray

Hydrogen : White

Oxygen : Red

Nitrogen : Blue

Based on the atom model and information above, what is the chemical formula of Niacin (Vitamin B3)?

• C₅H₆N₂O

• C₆H₅N₂O

• C₅H₆NO₂

• C₆H₅NO₂

Which one is NOT molecules of compounds?

• Br₂

• CO

• SO₂

• H₂O