Chemistry Fall Semester Final - 2024

A hypothetical element is made of two isotopes - one with a mass number of 25 and the other with a mass number of 26. If the atomic mass is 25.78, which isotope is more abundant?

• Isotope - 25
• Isotope - 26
• Impossible to tell
• Each isotope is equally abundant

A hypothetical element is found to have two isotopes. 57.38% of the sample is made up of Element-59 and 42.62% is Element-61. Use the given information, calculate its atomic mass.

• 60
• 59.85
• 60.15
• 5985.24

Calculate the average atomic mass for the following element given information about the isotopes Isotope 1 - mass # = 50, istope abundance = 90.92% Isotope 2 - mass # = 51, Isotope abundance = 0.257% Isotope 3 - mass # = 52, Isotope abundance = 8.82%

• 20.18
• 50.18
• 92.63
• 51.33

A sample of Iron contains two isotopes (Fe-55 and Fe-56). If the atomic mass of Iron is 55.85, what is the percent abundance of Iron-55?

• 15%
• 85%
• 50%
• 25%

The atomic mass of Holmium (Ho) is 164.93. If Holmium is composed of Ho-164 and Ho-166, what is the percent abundance of holmium-166?

• 53.5 %
• 46.5 %
• 50 %
• 99%

In a NEUTRAL atom, the number of ELECTRONS is equal to the:

• number of neutrons
• number of protons
• negative charge

Which subatomic particle determines the IDENTITY of the atom?

• Electron
• Neutron
• Proton

What part of the atom has a positive charge?

• Electron
• Neutron
• Proton

Which subatomic particle determines the PROPERTIES of the atom? How it will act in a chemical reaction.

• Electron
• Neutron
• Proton

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which part of the atom has a negative charge?

• Electron
• Neutron
• Proton