SCIENCE TEST UNIT 5 (2ND GRADE)

Name the states of matter

• plasma and gas

• solid, liquid, gas

• solid, liquid, gas and plasma

Is the smallest unit of an element.

• matter

• atom

• element

Is anything that has mass and volume.

• density

• matter

• element

Is a substance with specifi c properties made of

one kind of atom.

• element

• atom

• density

They have POSITIVE charge (+)

• protons

• neutrons

• electrons

They have NEGATIVE charge (-)

• protons

• neutrons

• electrons

What is the difference between the ATOMIC NUMBER and ATOMIC MASS of an atom?

• The atomic number represents the number

  of protons in the nucleus of an atom; the atomic mass

  represents the number of protons and neutrons in the

  nucleus of an atom.

• Represents the number of protons and neutrons in

  the nucleus of an element’s atom.

• Represents a tiny subatomic particle with a negative

  electric charge that orbits around the nucleus.

Look at the diagram of a lithium atom and answer the questions.

What is the atomic number of lithium?

• 4, because it has 4 NEUTRONS

• 3, because it has 3 PROTONS

• 7, because it has 4 NEUTRONS and 3 PROTONS

What is the atomic mass of lithium?

• 7 amu

• 3 protons

• 3 electrons

How does the numer of PROTONS (+) and ELECTRONS (-) compare?

• There are 4 NEUTRONS in the nucleus

• They are equal in number.

• There is one more NEUTRON in the nucleus.