Topic 7 Lesson 1: Atomic Theory

The mass of the electron is

• about equal to the neutron

• almost the same as the proton

• very small compared to the proton

• very large compared to the neutron

Which statement is the BEST definition of an atom?

• Anythng that has mass and takes up space

• The smallest particle that has the properties of an element

• A substance that cannot be broken down chemically into a simpler substance

• The smallest unit of a substnace that exhibits all the properties characteristics of that substnace.

Why can a liquid change to take the shape of its container but NOT expand to fill the container itself?

• because the particles of a liquid are held together loosely enough to flow, but not so loose that they expand.

• because the particles of a liquid have a definite shape but no definite volume.

• because the particles of a liquid are the result of both dolid and gaseous phases combining

Describe the composition of the nucleus of an atom.

• composed of protons

• composed of protons and neutrons

• composed of protons and electrons

• composed of proton, neutrons, and electrons

Which statement is accurate for protons and neutrons?

• both have a neutral charge

• both have a positive charge

• both are located in the nucleus

• both located outside the nucleus

The nucleus is the dense center of the atom composed of protons and neutrons. Surrounding the nucleus is an electron cloud composed of electrons.

• Atom

• Cell

• Element

• Nucleus

Which is a sub-atomic particle?

• compound

• electron

• neuron

• atom

The simplest form of all matter are small particles called

• atom

• cell

• element

• molecule

When air freshener is sprayed in a room the smell spreads throughout the room. Gases take the shape and volume of their container because the particles ______.

• are close together and in a fixed pattern

• are far apart from one another and in a fixed pattern

• are close together and unable to move past one another

• are spread apart from one another and able to move about.

Which statement about atomic structure is incorrect?

• Protons are located in the nucleus

• Protons and electrons have the same mass.

• Protons and electrons have opposite charges.

• Neutral atoms contain the same number of protons and electrons.