Download What does an elements atomic # tell us about the element?

Atoms Pre-Test
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Name the three subatomic particles.
Gravity’s affect on an object is termed: ___
What does an elements atomic # tell us about the
element?
What type of bond is formed through shared electrons?
Where are electrons found in terms of an atom?
What does an elements atomic mass tell us about the
element?
What type of bond is formed through transferred
electrons?
_____________ is two or more elements chemically
bonded together.
How many atoms are in the following: (C0)₂H₃
________________ is anything that takes up space &
contains mass.
Protons, neutrons, & electrons
1. Name the three subatomic particles.
2. Gravity’s affect on an object is termed: ___
weight
3. What does an elements atomic # tell us about the element?
# of protons in the element
4. What type of bond if formed through shared electrons?
covalent
5. Where are electrons found in terms of an atom?
Outside of the nucleus
6. What does an elements atomic mass tell us about the element?
# of protons & neutrons in the element
7. What type of bond is formed through transferred electrons?
ionic
compound
8. _____________
is two or more elements chemically bonded
together.
9. How many atoms are in the following: (C0)₂H₃ 7
matter
10. _______________
is anything that takes up space & contains mass.
Matter, Elements, Atoms,
Compounds, & Isotopes
Do they really matter?
Matter
Mass vs
Weight
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Volume
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Anything that has volume and
mass
Mass & weight are not the same
Weight – is the force of gravity on
an object
Mass – how much is in an object
Is the amount of space taken up
by an object
Ex. Piece of gold – has mass and
volume, therefore is matter
Elements
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Common
Elements
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All matter is composed of
elements
Substances that cannot be broken
into simpler substances by
chemical means
Name
Oxygen
Nitrogen
Hydrogen
Gold
Silver
Symbol
O
N
H
Au (latin)
Ag (latin)
Particle
Model
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
Atom
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Developed by John Dalton 150
years ago
each element is made up of tiny
particles called atoms
The smallest part of an element
that has all the properties of that
element
Proton &
Neutron
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Electron
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Make up the nucleus of the atom
99.9% of atom
Proton – positive charge
Neutron – no charge
Negative charge.
Moves around the nucleus
1836 times lighter than Proton
Neutron
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
Ex. Helium
Atom
Makes up part of the nucleus
Slightly heavier than proton
Atomic
Number
Atomic Mass
# of protons and electrons in an atom


Average # of protons & neutrons in
an atom
Number of neutrons = atomic mass
- atomic number
Drawing an Atom of
Carbon
6
C
12.011
Atomic #
= # of p+ and # of e-
Carbon has 6 p+ and 6 e-
Atomic Mass
minus Atomic # = # of n0
Carbon has 6 n0
Ex.
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Potassium - K
Atomic # = 19
Atomic mass = 39
K nucleus contains 19 protons
39 – 19 = 20 neutrons
How many electrons?
Same as # Protons (19)
Compounds
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Molecules
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A substance that contains 2 or
more elements chemically bonded
together
Ex. H – H – O = water
Smallest part of a compound that
still has all the properties of that
compound
Compound can have properties
entirely unlike the elements of
which it is made
Ex.

H2O = Water
Oxygen
&
Hydrogen
Explosive Gases
Isotopes

Atoms of the same chemical
element with different atomic
masses
Chemical bonds: an attempt to fill electron shells
1.
2.
3.
Ionic bonds –
Covalent bonds –
Metallic bonds
IONIC BOND
bond formed
between
two ions by the
transfer of electrons
Formation of Ions from Metals

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Ionic compounds result when metals react
with nonmetals
Metals lose electrons to match the number
of valence electrons (typically 8) of their
nearest noble gas
Positive ions form when the number of
electrons are less than the number of
protons

Group 1 metals 
ion 1+
Group 2 metals 
ion 2+
Group 13 metals 
ion 3+
Ionic Bonds: One Big Greedy Thief
Dog!
COVALENT BOND
bond formed by the
sharing of electrons
Reading Chemical Compounds
How many different elements?
How many total atoms?
H2O
NaCl
H2SO4
Be(OH)2
1. When an atom gains or loses an
electron it is now called an ____.
Ion
2. How many different elements are
in the following compound?
(CH3)2CO
Answer- 3
3. How many total atoms are in
the following compound?
(CH3)2CO
Answer- 10
4. The atomic number tells how
many ____________ are in the
element.
Protons and electrons