Atomic Composition Unit 3 – Atomic Structure Mrs. Callender.
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Transcript of Atomic Composition Unit 3 – Atomic Structure Mrs. Callender.
Atomic CompositionUnit 3 – Atomic Structure
Mrs. Callender
Write down three things you know about the atom.
ELECTRON e-
Negatively Charged
Atomic Mass – 0.0005 amu
Basically round to zero amu
3 Major Subatomic Particles
PROTON p+
Positive Charge
Mass of 1.007 amu
Found in nucleus of atom
Neutron no
No charge - “neutral”
Mass of 1.0009 amu
Found in Nucleus
Oth
er S
ub
ato
mic
P
artic
les
Com
pu
ter
Gen
era
ted
pic
ture
of tw
o b
om
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ed
ato
ms.
Symbol -ZAll atoms of
the same element have
the same number of protons in
the nucleus.
Atomic Number
ATOMIC NUMBER = NUMBER OF PROTONS
Symbol -AMass comes from the nucleus of the atom.
Mass number = # protons + # neutrons
Mass Number
No overall Charge
Number of protons and electrons are
the same
Neutral Atom -0r- Ground State
Ion
There was either:
1. Gain of electron(s)
2. Loss of electron(s)
What if it is not neutral?
X+
X-
Metals vs. NonmetalsMETALS LOSE ELECTRONS BECOMING POSITIVELY CHARGED.
NONMETALS GAIN ELECTRONS BECOMING NEGATIVELY CHARGED.
Example Using the Bohr Model
Na is a metal and wants to lose an electron so it has a full energy level of electrons.
Cl is a nonmetal and wants to gain and electron so it can have a full energy level.
1s22s22p6
3s1
1s22s22p63s2
3p5
Example Using the Bohr Model
11 protons and 10 electrons make an ion with a +1 charge.
17 protons and 18 electrons make an ion with a -1 charge.
1s22s22p6 1s22s22p63s2
3p6
How do we write all of this information?
Complete Chemical Symbol
Write the symbol for the atom with 28 protons, 28 electrons and 31 neutrons.
Ni1. Look up the symbol by using the number of protons. REMEMBER: the number of protons is the same as the atomic number.
2. Write the number of protons in the lower left hand side of the element.
28
3. Add the # of neutrons to the number of protons. REMEMBER - this is the atomic mass.
59
4. Check to see if you have an atom or an ion. If the number or protons does not equal the number of electrons then you will need to add a + charge or a – charge.
How do we write all of this information?
Complete Chemical Symbol
Write the symbol for the ion with 8 protons, 10 electrons and 8 neutrons.
O1. Look up the symbol by using the number of protons. REMEMBER: the number of protons is the same as the atomic number.
2. Write the number of protons in the lower left hand side of the element.
8
3. Add the # of neutrons to the number of protons. REMEMBER - this is the atomic mass.
16
4. Check to see if you have an atom or an ion. If the number or protons does not equal the number of electrons then you will need to add a + charge or a – charge.
-2
How do we write all of this information?
Complete Chemical Symbol
Write the symbol for the ion with 20 protons, 18 electrons and 20 neutrons.
Ca 1. Look up the
symbol by using the number of protons. REMEMBER: the number of protons is the same as the atomic number.
2. Write the number of protons in the lower left hand side of the element.
20
3. Add the # of neutrons to the number of protons. REMEMBER - this is the atomic mass.
40
4. Check to see if you have an atom or an ion. If the number or protons does not equal the number of electrons then you will need to add a + charge or a – charge.
+2
How do we write all of this information?
Element name – atomic mass
How many protons, neutrons and electrons are in Tantalum-181.
1. The number of protons comes from the atomic number.
2. The number of electrons equals the number protons because this is a neutral atom.
Protons – 73 Electrons – 73 Neutrons – 108
3. The number of neutrons is equal to the mass number minus the atomic number.