Biology: Chapter 2

________ is anything that has weight and takes up space.

Matter

_______ are the building blocks of matter.

Atoms

_______ are pure substances made of one kind of atom.

Elements

_______ are a combination of atoms.

Molecules

The three subatomic particles are:

Protons, Neutrons, and Electrons

Which subatomic particle is negatively charged?

Electrons

Which subatomic particle is positively charged?

Protons

Which subatomic particle has no charge?

Neutrons

The nucleus is collection of which two subatomic particles?

Protons and Neutrons

Electrons are organized into shells called _______.

Electron clouds

_______ are atoms of the same element with a different number of neurons.

Isotopes

_______ are unstable isotopes that emit radiation.

Radioisotopes

While harmful, _______ can be used for a number of medical uses including imaging the body (MRI), killing bacteria in food, and sterilizing medical equipment.

Radiation

The first electron shell holds haw many electrons?

2

How many electrons can be held in the subsequent electron shells?

8

The three chemical bonds are:

Covalent, Ionic, and Hydrogen

This chemical bond shares electrons between atoms.

Covalent Bonds

This chemical bonds has oppositely charged atoms and are attracted to each other due to electron transfer.

Ionic Bonds

This chemical bond has positively charged molecules and are held together via hydrogen attraction.

Hydrogen Bonds