Download What is matter?

Name __________________
Lakeland High School
Date ___________________
Biology/Ms. Tsai
Basic properties of matter
What is matter?
Anything that takes up space
Three states: solid, liquid, gas
All matter is made up atoms
Atom –
the smallest unit into which an element can be
divided and still have all the properties of that
element.
Some examples of elements are:
Gold, silver, oxygen, iron, carbon or copper
An atom has 3 types of particles:
Proton –
Has a positive charge
Found inside the nucleus.
Electron –
Has negative charge
“floats” around nucleus
Neutron –
Has no charge
Also found in nucleus
The number of protons in the center of the atom (called the
nucleus) gives the atom its identity. Each element has a different
number of protons in its nucleus. For example:
All atoms with 1 proton are hydrogen
All atoms with 6 protons are carbon
The number of protons in an atom gives it its
atomic number.
What are the atomic numbers of the following elements?
Sodium (Na) _____11______
Nitrogen (N) ______7_____
Oxygen (O) ______8_____
Each atom in an element has an equal number of protons and
electrons, so that an atom is electrically balanced (positives equal
negatives).
Another important number when talking about atoms is the mass
number
What is mass?
The amount of matter in a substance.
The only 2 particles of an atom that have mass are the proton and
the neutron, so the number of protons added to the number of
neutrons gives an atom its mass number
This number is found underneath the symbol for the element on the
periodic table.
What is the mass number of the following elements?
Sodium (Na) ______23_______
Nitrogen (N) ______14_______
Oxygen (O) ______16______
=
Since atomic number tells us __protons___ and __electrons__
Mass number tells us _protons__and _neutrons_.
How can we figure out just the number of neutrons?
Mass number
= protons and neutrons
Atomic number
= protons
So, subtract atomic number from mass number to get
neutrons
Complete the table below based on what you’ve learned and using
the periodic table:
Element
Helium (He)
# Electrons
# Protons
2
2
7
7
6
6
10
10
5
5
20
20
19
19
53
53
Nitrogen (N)
Carbon (C)
Neon (Ne)
Boron (B)
Calcium (Ca)
Potassium (K)
Iodine (I)
# Neutrons
4–2 =
2
14 – 7 =
7
12 – 6 =
6
20 – 10 =
10
11 – 5 =
6
40 – 20 =
20
39 – 19 =
20
127 – 53 =
74
More about electrons
Electrons, as we’ve said, are negatively charged. They are found
“swarming” around the nucleus of the atom. Because they have a
charge, they repel other negatively charged items, like electrons of
other atoms.
Electrons swarm in rings around the nucleus. These rings are
called orbitals. The first orbital around the nucleus can hold 2
atoms-all the others can hold 8.
Atoms prefer to be in the “full” state-holding all the electrons that
they can. So electrons are very often added or lost from orbital
rings. This is called bonding.
Two types of bonding –
Covalent –
When electrons are shared between atoms
Ionic –
When electrons are transferred between atoms, one
atom gains an electron, the other loses one.
This results in a charged atom.
Summary Questions
1. What are the 3 components of an atom, and what are their
charges?
2. Using the Periodic Table, fill in the following chart
Element
symbol
F
# Electrons
# Protons
# Neutrons
Nb
Hg
Pa
3. What’s the difference between ionic bonds and covalent
bonds?