PS.Chem1 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

If you start with 50,000 atoms of uranium-238, how many will remain after one half-life (4.5 billion years)?

Back

25,000 atoms will remain after one half-life.

Front

What are isotopes?

Back

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

Front

How many neutrons are in an atom of Nitrogen-16?

Back

There are 9 neutrons in an atom of Nitrogen-16.

Front

What did Rutherford's gold foil experiment demonstrate about atomic structure?

Back

It demonstrated that most of the atom is empty space, as most alpha particles passed straight through the foil.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the significance of the periodic table in chemistry?

Back

The periodic table organizes elements based on their atomic number, electron configuration, and recurring chemical properties.

Front

What is an electron configuration?

Back

Electron configuration is the distribution of electrons among the orbitals of an atom.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance made of only one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

Front

What is the role of neutrons in an atom?

Back

Neutrons help stabilize the nucleus of an atom and contribute to its mass.