unit 1 lesson 1 part2 prep1

When an atom is changed into an ion the..................... is changed.

• number of protons

• number of neutrons

• number of electrons

• mass number

A lithium atom ( Li ) changes into a lithium ion (Li+), which means that it .......

• gains one proton.

• gains one electron.

• loses one proton.

• loses one electron.

During the chemical reaction, a magnesium atom (12Mg) loses its outer electrons and changes into...............

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The only nonmetal that exists in a liquid state is............................

• bromine

• chlorine

• hydrogen

• nitrogen.

All of nonmetals don’t conduct electricity, except.......................

• bromine

• aluminium

• graphite

• mercury

In a negative ion, the number of protons is ....................... the number of electrons.

• less than

• more than

• equal to

• no correct answer

All of these elements can form negative ions, except.........................

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When a nitrogen atom (7N) gains electrons to complete its outer shell, it becomes .............

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The number of electrons in oxygen ion (O-2) is..................electrons.

• 6

• 8

• 10

• 12

‘Which of the following figures represents the chloride ion (CI-) ? Fig. (corre).

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