Chemistry Midterm Review

Front

What is the half-life of a radioactive isotope?

Back

The half-life is the time required for half of the radioactive atoms in a sample to decay.

Front

How do you calculate the remaining amount of a substance after a certain number of half-lives?

Back

Use the formula: Remaining amount = Initial amount × (1/2)^(time elapsed / half-life).

Front

What is the balanced equation for the reaction of zinc with hydrochloric acid?

Back

The balanced equation is: 1 Zn + 2 HCl → 1 ZnCl₂ + 1 H₂.

Front

What is the name of the compound FeCl₂?

Back

The name of FeCl₂ is iron (II) chloride.

Front

How do you convert Celsius to Kelvin?

Back

To convert Celsius to Kelvin, add 273.15 to the Celsius temperature.

Front

What is the formula to convert 100°C to Kelvin?

Back

100°C = 100 + 273.15 = 373.15 K.

Front

How many neutrons are in the isotope C-14?

Back

C-14 has 8 neutrons (14 - 6 protons = 8 neutrons).

Front

What is the definition of an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures that the law of conservation of mass is obeyed, meaning the number of atoms of each element is the same on both sides of the equation.

Front

What is the difference between ionic and covalent bonds?

Back

Ionic bonds involve the transfer of electrons from one atom to another, while covalent bonds involve the sharing of electrons between atoms.