Front

Which letter represents an electron? Options: A, B, C, D, E

Back

E

Front

Which of the following is correct?
Options:
Protons (positive); Neutrons (negative); Electrons (neutral)
Protons (positive); Neutrons (neutral); Electrons (negative)
Protons (negative); Neutrons (neutral); Electrons (positive)
Protons (neutral); Neutrons (positive); Electrons (negative)

Back

Protons (positive); Neutrons (neutral); Electrons (negative)

Front

How many neutrons does Phosphorus have?

Back

16

Front

What is the atomic number of this atom?

Back

7

Front

How many valence electrons does this atom have?

Back

1

Front

What is the mass of this atom?

Back

6

Front

How many electrons can fit on the first two shells (energy levels)?

Back

2 electrons on the first and 8 electrons on the second

Front

What determines the identity of an element?

Back

The number of protons

Answer explanation

the mass can be different, even with the same element. For example, Carbon usually has a mass of about 12 amu, but there are carbons with a mass of 13 and even 14 amu. Electrons usually equal the protons, but electrons can be gained or lossed by an atom (ions)

Front

What is the first thing a student should count to identify an element?

Back

C

Answer explanation

She needs to know the number of protons. This is also the atomic number, which identifies the element.

Front

What are the vertical columns on the periodic table called?

Back

groups