2.2 PW - Quiz 2 Practice Questions

There are two naturally occurring isotopes of Bromine. 50.69% of Bromine exists as Br-79 and 49.31% exists as Br-81. Which of the following would be the correct numerical setup needed to calculate the average atomic mass of Bromine?

• (79 * 0.4931) + (81 * 0.5069)

• (79 * 49.31) + (81 * 50.69)

• (79 * 0.5069) + (81 * 0.49231)
• (79 * 50.69) + (81 * 49.31)

An excited potassium atom emits a specific amount of energy when one of its electrons moves from

• the first shell to the fourth shell

• the second shell to the fourth shell

• the fourth shell to the fifth shell

• the fourth shell to the second shell

Tags

NGSS.HS-PS1-4

NGSS.HS-PS4-3

Which two elements are present in this mixture?

• A and Q

• A and E

• G and Q

• G and E

Tags

NGSS.MS-PS1-1

Each line in the spectra represents the energy

• absorbed as an atom loses an electron

• absorbed as an atom gains an electron

• released as an electron moves from a lower energy state to a higher energy state

• released as an electron moves from a higher energy state to a lower energy state

Tags

NGSS.HS-PS1-2

The mass of en electron is

• equal to the mass of a proton

• equal to the mass of a neutron

• greater than the mass of a proton

• less than the mass of a proton

What is the net charge of an ion that has 15 protons, 16 neutrons, and 18 electrons?

• +2

• -2

• +3

• -3

Tags

NGSS.MS-PS1-1

When an F atom becomes an F^- ion, the F atom

• gains a proton

• loses a proton

• gains an electron

• loses and electron

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the number of electrons in a potassium atom?

(hint: what can you assume about an ATOM vs. an ion...)

• 18

• 19

• 20

• 39

Tags

NGSS.HS-PS1-1

Which statement describes the charge and the radius of a magnesium ion formed when a magnesium atom loses two electrons?

• The Mg ion is positive and has a radius larger than the Mg atom.

• The Mg ion is negative and has a radius larger than the Mg atom.

• The Mg ion is negative and has a radius smaller than the Mg atom.

• The Mg ion is positive and has a radius smaller than the Mg atom.

Answer explanation

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which ion has a charge of -2?

• A

• E

• G

• J

Tags

NGSS.HS-PS1-1