What parts make up an atom? Coach Scruggs 8 th Grade

What makes up an atom? It is hard to believe how tiny an atom is. Yet, the tiny atom is made up of even smaller parts. Can you imagine how small these parts are? An atom has 3 main parts: protons, neutrons, and electrons. Protons and neutrons make up the center of an atom. The center part of an atom is called the nucleus. The electrons are outside the nucleus. They spin around the nucleus at very great speeds. Electrons are much smaller than protons and neutrons.

Parts of an Atom Nucleus: the center part of an atom Nucleus: the center part of an atom Proton: found inside the nucleus; a proton has a plus (+) electrical charge Proton: found inside the nucleus; a proton has a plus (+) electrical charge Neutron: found inside the nucleus; a neutron has no electrical charge Neutron: found inside the nucleus; a neutron has no electrical charge Electron: moves around the nucleus; an electron has a minus (-) electrical charge Electron: moves around the nucleus; an electron has a minus (-) electrical charge

Protons and electrons have electrical charges. Each proton has a positive (+) charge. Each proton has a positive (+) charge. Each electron has a negative (-) charge. Each electron has a negative (-) charge. A neutron is neutral. It has no charge. An atom has the same number of protons as electrons.

PROTONS (+) = ELECTRONS (-) This means that the number of plus (+) charges equals (=) the number of minus (-) charges. They balance each other. Because of this, the entire atom has no charge.

PROTONS (+) = ATOMIC NUMBER The atomic number is also the same as the number of protons These three things are equal: P rotons = E lectrons = N umber (atomic) If you know any of these numbers, you know the number of the other two. They are the same!

Answer these questions. 1. Name the parts that make up a nucleus. 2. A proton is ____larger___ (larger, smaller) than an electron. 3. An electron is ______smaller (larger, smaller) than a neutron. 4. A proton has _____positive__ (a positive, a negative, no) charge. 5. An electron has ____negative___ (a positive, a negative, no) charge. 6. A neutron has __no____ (a positive, a negative, no) charge. 7. An entire atom has _____positive___ (a positive, a negative, no) charge.

Name of Element Symbol Atomic Number Number of Protons Number of Electrons 1.OxygenO888 2.CalciumCa IodineI NalgoenNa SilverAg Sulfur S MercuryHg IronFe You will need your Periodic Table to fill in some spaces.

ATOMIC WEIGHT The weight of an atom is the weight of its nucleus. A nucleus contains protons and neutrons. Therefore, the number of protons plus the number of neutrons gives us the atomic weight of an atom. Electrons are so light, that they are not counted in the atomic weight. Every atom has weight. The weight of an atom is called its atomic weight. An atomic weight is not an exact scale reading of weight – like grams or ounces. It is a way of comparing the weight of one atom against the weight of another atom.

ATOMIC WEIGHT Each proton is given a weight of ONE. Each proton is given a weight of ONE. Each neutron is given a weight of ONE. Each neutron is given a weight of ONE. Each different kind of atom has its own number of protons. Each different kind of atom has its own atomic number.

ATOMIC WEIGHT for Lithium Example: A lithium atom has 3 protons and 4 neutrons. The atomic weight is 7 (3 + 4 = 7)

Answer these questions. 1. What is the center part of the atom? Nucleus 2. What parts make up the nucleus? Protons and Neutrons 3. The weight of an atom is the weight of its ___Protons____ and ___Neutrons___. 4. Fill in the blanks. ATOMIC WEIGHT=Protons_+Neutrons____

Name of Element Symbol Number of Protons Number of Neutrons Atomic Weight 5.NeonNe CobaltCo GoldAu ChlorineCl ThoriumTh LeadPb NickelNi ChromiumCr SiliconSi TungstenW Now fill in the chart.

ROUNDING Atomic Weights Atomic weights are not written as whole numbers. They are written as decimals. Atomic weights are not written as whole numbers. They are written as decimals. Example: Copper We round off the decimal to its nearest whole number. If the decimal is.5 or greater we round to the next higher number. If the decimal is less than.5 we round down. We round off the decimal to its nearest whole number. If the decimal is.5 or greater we round to the next higher number. If the decimal is less than.5 we round down. Example: Copper 64

Element Listed Atomic Weight Rounded-Off Atomic Weight 1.Copper Calcium Fluorine Strontium Barium Titanium Magnesium Argon Erbium Zirconium Use this knowledge to fill in the chart. The first two are done as examples.

What do the pictures show? Figures D and E show atoms. Study each figure and answer the questions about each. 1. How many protons does the atom in Figure E have? 2 2. How many neutrons? 2 3. How many electrons? 2 4. What is the atomic weight of this atom? 4 5. What is the name and symbol of this atom? Name Helium______ Symbol __He__________ Figure E

What do the pictures show? Figures D and E show atoms. Study each figure and answer the questions about each. 1. How many protons does the atom in Figure D have? 9 2. How many neutrons? How many electrons? 9 4. What is the atomic weight of this atom? What is the name and symbol of this atom? Name ___Neon______ Symbol Ne______ Figure D

Completing Sentences Complete the sentences with the choices below. Two of these may be used twice. Two of these may be used three times. WORD BOX plusnoneutrons atomic number atoms1circleelectronsminusprotons All matter is made up of tiny __atoms____. The three main parts of an atom are protons____, _____neutrons__, and ____electrons____. A nucleus is made up of ___proton___ and _____neutron__. Electrons __minus__ the nucleus. A proton has a __positive__ charge; an electron has a _negative charge; and a neutron has a _no_ charge.

Completing Sentences Complete the sentences with the choices below. Two of these may be used twice. Two of these may be used three times. WORD BOX plusnoneutrons atomic number atoms1circleelectronsminusprotons An entire atom has ___no__ charge. Protons = electrons = ___neutrons__ The atomic weight of an atom is the weight of its __circle__ and _atoms__. Each proton or neutron is give a weight of __1___. In figuring atomic weight, we do not count the weight of an atoms __number___.

Matching Match the two lists. Write the correct letter on the line next to each number. 1. _c_ protons and neutronsa. no charge 2. _e_ electronb. add an atoms protons and neutrons 3. _d_ protonc. make up a nucleus 4. _a_ neutrond. positive charge 5. _b_ to find atomic weighte. negative charge