Semester Chemistry Review

Alkali metals are extremely reactive because they

• have every small atomic masses.

• are not solid at room temperature.

• have one valence electron that is easily removed to form a positive ion.

• have two valence electrons that form compounds with calcium and magnesium.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

In the image, which column are the noble gases located?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-1

Which diagram correctly shows the trend for electronegativity?

• A

• B

• C

• D

Which diagram correctly shows the trend for atomic radius?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The time taken for half of an amount of radioactive atoms to decay.

• Nuclear fusion

• Full-life

• Dead time

• Half-life

Tags

NGSS.HS-PS1-8

What do these symbols represent?

• alpha particle

• beta particle

• neutron

• gamma ray

Tags

NGSS.HS-PS1-8

How many neutrons are in this isotope of Uranium?

• 235

• 92

• 327

• 143

Tags

NGSS.HS-PS1-8

What is the mass number of at isotope that has 20 protons, 21 neutrons and 18 electrons?

• 18

• 20

• 21

• 41

What happens to the atomic number during alpha decay?

• The atomic number decreases by 4

• The atomic number increases by 1

• The atomic number decreases by 2.

• The atomic number stays the same.

Tags

NGSS.HS-PS1-8

If 10 mg of iodine 131 is given to a patient, how much is left after 24 days? The half-life of iodine-131 is 8 days.

• 25mg

• 1.25g

• 10g

• 10mg