1.1.4-5 - Relative Electrical Charge of Subatomic Particles/Size & Mass of Atoms

State the relative masses and relative charges of the proton, neutron, and electron.

• Proton: 1, +1

• Neutron: 1, 0

• Electron: 1/2000 (very small), -1

Explain why atoms are electrically neutral.

They have the same number of electrons and protons.

What is the radius of an atom?

0.1 nm

What is the radius of a nucleus and what is it compared to that of the atom?

• 1 × 10^-14 m

• 1/10000

What name is given to the number of protons in the nucleus?

atomic number

Atoms of the same element have the same number of which particle in the nucleus?

protons

Where is the majority of mass of an atom?

nucleus

What is the mass number?

Total number of protons and neutrons.

How does one calculate the number of neutrons using mass number and atomic number?

Subtract the atomic number from the mass number.

What is an isotope? Do isotopes of a certain element have the same chemical properties?

• Atoms of the same element (same proton number) that have a different number of neutrons.

• They have the same chemical properties as they have the same electronic structure.