Language of chemistry

How many electrons are present in a nitride ion?

• 6

• 5

• 8

• 10

What is the formula of the compound formed between calcium and oxygen?

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• 
• 
• 

Which one of the following has 4 electrons in its valence shell?

• C

• S

• P

• F

A molecule of a compound is electrically _____.

• neutral

• positive

• negative

• charged

Aurous has a valency of ___.

• +1

• +2

• +3

• +4

Examples of elements which do not show variable valency are ______.

• Cu and Fe

• Cu and Zn

• Zn and Al

• Sn and Al

When an element exists as a molecule, each unit consists of two or more ____________.

• ions

• radicals

• atoms

• neutrons

The symbol of ammonium radical is ______.

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• 
• 
• 

Phosphorus is an example of __________.

• monoatomic molecules

• diatomic molecules

• triatomic molecules

• polyatomic molecules

• sodium hydrogen carbonate.

• sodium oxide.

• sodium sulphide.

• sodium hydroxide.