Chemistry Quizs

Total number of neutrons for the following isotope

• 0

• 1

• 2

• 3

Complete the nuclear fission reaction: @@^{235}_{92}U + ^{1}_{0}n \rightarrow ^{142}_{56}Ba + ^{91}_{36}Kr + 3@@ What is missing after the 3 in the equation?

• @@^{1}_{0}n@@

• @@^{2}_{1}H@@

• @@^{0}_{-1}e@@

• @@^{4}_{2}He@@

Oxygen is in column 16.

• It has 5 valence electrons

• It has 6 valence electrons

• It has 7 valence electrons

• It has 8 valence electrons

Total number of protons in the nucleus of an atom with two electrons in its first shell and six electrons in its second shell.

• 6

• 7

• 8

• 9

Elements in Group 17 include Bromine, Chlorine, Fluorine, and Iodine. What happens to the valence electrons and energy shells as you go down the column?

• Valence electrons increase and energy shells stay the same

• Valence electrons stay the same (7) and the energy shells increase

• Valence electrons decrease and energy shells increase

• Valence electrons stay the same and energy shells decrease

The difference between oxygen-16 and oxygen-18

• Oxygen-16 has 8 neutrons and oxygen-18 has 10 neutrons.

• Oxygen-16 has 6 neutrons and oxygen-18 has 8 neutrons.

• Oxygen-16 has 10 neutrons and oxygen-18 has 12 neutrons.

• Oxygen-16 has 8 neutrons and oxygen-18 has 6 neutrons.

Mass number of every chlorine atom.

• 32

• 34

• 35

• 36

After 2000 million years, what percentage of uranium-235 remains?

• 5%

• 10%

• 15%

• 20%

The atomic radius of elements in a period (row) ______ as you move left to right.

• increase

• decrease

• stay the same

• fluctuate

Atomic number for the following isotope

• 1

• 2

• 3

• 4