The Foundations of Matter

The Foundations of Matter-8th Grade

Atoms

• Atoms make up all elements All atoms are made of these three components: protons, neutrons and electron

• Every elements has its own number of protons which distinguishes it from other elements

Three Smaller Components of Atoms

• Protons have a positive charge and are located in the nucleus of an atom

• Neutrons have a neutral charge, or no charge, and are located in the nucleus of an atoms

• Electrons have a negative charge and are located outside of the nucleus in the electron cloud

• Neutrons give you the number of isotopes in an atom

• In a neutral atom, the number of protons and electrons are the same

Elements

• Elements can be either metals, nonmetals or metalloids

• Metals are shiny, good thermal and electrical conductors, malleable and ductile

• Nonmetals are dull, poor thermal and electrical conductors, brittle, and unmalleable

• Metalloids have properties of both metals and non metals

Elements Labeled on the Periodic Table

• The atomic number is also the number of protons and the number of electrons

• The element symbol is either one capital letter or one capital and one lowercase letter

• The atomic weight is also called the atomic mass

Atom Charges and Energy Levels

• The charge of an atom is determined by the number of protons and electrons

• Protons and neutrons contribute most to the mass of an atom

• The electrons will give you the reactivity of an atom

• Valence electrons are found in the outermost energy shell (or ring) and determine reactivity

Calculating Atomic Mass

• To find the atomic mass of an atom, you can use the formula M.A.N.

• M.A.N. stands for atomic Mass, Atomic number and Neutrons

• The formula is M-A=N or Mass minus atomic number equals neutrons

• Ex: To find the mass of an atom that has 5 protons and electrons (also the atomic number) and 10 neutrons, I would take 5+10= 15 for the atomic mass.

• You find the number of neutrons by subtracting the atomic mass minus the atomic number

Multiple Choice

The three smaller components that make up atoms are -

• Neutrons,protons,and ions

• Neutrons,electrons,and protons

• Protons,ions,electrons

• electrons,neutrons and ions

Multiple Choice

Which of the following lists the two particles found together inside the nucleus of an atom?

• Protons and ions

• Neutrons and electrons

• Protons and neutrons

• Electrons and protons

Multiple Choice

A neutral atom has an equal number of positive and negative charges. If a neutral fluorine atom has 9 protons and 10 neutrons, how many electrons will it have?

• 10

• 9

• 8

• 7

Multiple Choice

If an atom has six positively charged subatomic particles, which of the following must it also have in order to become a neutral atom?

• Twelve protons

• Six neutrons

• Three electrons

• Six electrons

Multiple Choice

If you change the number of neutrons in an atom, you will also change its-

• Charge

• Element

• Number

• Isotope

Multiple Choice

The nucleus of the atom contains 8 protons and 9 neutrons.The atom is electrically neutral.How many electrons does this atom have?

• 4

• 8

• 9

• 15

Multiple Choice

If an atom has 17 protons,18 neutrons, and 17 electrons, what is the mass of this atom?

• 17

• 18

• 35

• 52

Multiple Choice

The charge of an atom is determined by the -

• Shape of the electron cloud

• Atomic mass of the element

• radius of the outermost electron

• Number of protons and electrons

Multiple Choice

Which of the following list the two subatomic particles that contribute the most to the mass of an atom?

• Protons and electrons

• Protons and neutrons

• Neutrons and electrons

• electrons and ions

Multiple Choice

What is the name for the type of subatomic particle that is electrically neutral and found in the nucleus of an atom?

• Proton

• Neutron

• Ion

• Electron

Multiple Choice

Which particles would you find in the nucleus of an Atom?

• Protons and neutrons

• Electrons and protons

• Neutrons and electrons

• Electrons only

Multiple Choice

What is the mass of an atom with seven protons, seven neutrons, and eight electrons?

• 14

• 20

• 5

• 4

Multiple Choice

Copper’s atomic number is 29. This means that copper has-

• 29 protons in its nucleus

• 29 atoms in every molecule

• A boiling point of 29 degrees

• An atomic radius of 29 micrometers

Multiple Choice

The table provides information on four different elements. Which element has six protons in its nucleus?

• Boron

• Carbon

• Nitrogen

• Oxygen

Multiple Choice

The atomic number of nickel is 28. This means that it has 28-

• Different isotopes

• Oxidation states

• Electron energy levels

• Protons in its nucleus

Multiple Choice

The number of valence electrons in an atom determines its-

• Atomic number

• Chemical reactivity

• Number of protons

• Atomic mass

Multiple Choice

Which of the following distinguishes an element from all other elements?

• Its number of protons

• Its color in solid form

• Its phase at room temperature

• Its group in the Periodic Table

Multiple Choice

Molybdenum has an atomic number of 42. This means that molybdenum-

• Has a freezing point of 42 degrees

• Belongs in Group 42 on the Periodic Table

• Can form 42 bonds with other atoms

• Contains 42 protons in its nucleus