Chemistry First Semester Final Exam Review 24/25

Front

What is the average atomic mass of an element with isotopes of 75.23 amu (24.1%), 74.61 amu (48.7%), and 75.20 amu (27.2%)?

Back

74.92 amu

Front

Identify the equipment used to create a spark for ignition in a laboratory.

Back

Striker

Front

Calculate the density of a substance given its mass (923 g) and volume (20312 cm³).

Back

0.0454 g/cm³

Front

What is the mass number of an atom with 7 total nucleons?

Back

7

Front

Who was the first person to propose the concept of an atom?

Back

Democritus

Front

Define atomic mass unit (amu).

Back

A unit of mass used to express atomic and molecular weights, defined as one twelfth of the mass of a carbon-12 atom.

Front

What is the significance of significant figures in calculations?

Back

Significant figures indicate the precision of a measurement and help convey the uncertainty in calculations.

Front

Explain the concept of isotopes.

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.

Front

What is the formula for calculating density?

Back

Density = Mass / Volume

Front

Define the term 'nucleon'.

Back

A nucleon is a collective term for protons and neutrons in an atomic nucleus.