Select all that apply.

1: Which of the following particles are of approximately equal mass?

A: protons
B:electrons
C:neutrons
D:quarks
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2: If the atomic number of an element is 16, then it has 16 electrons.

True
False
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3: An unknown substance is tested and found to have the following physical properties:

brittle
fair conductor of electricity
dull (not shiny)

The substance is most likely a _____.

A:metal
B:metalloid
C:nonmetal
D:can not be determined without more data
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