Download - I. What is an atom?
I. What is an atom?
Atoms are the basic unit of matter All matter is made up of tiny atoms
Atom
Atoms are the building blocks of all matter
water
Molecule Atom
O
H H
Subatomic
Subatomic Particles (Draw this)
Proton Neutron Electron
Location in the Atom
Mass
Charge
Structure of an atom
There are 3 subatomic particles in an atom Proton Neutron Electron
THE PROTON
p+ •Found in the nucleus •Heavy: 1 amu• Positive: +1
THE NEUTRON
N° • Located in the
nucleus.•Heavy: 1 amu• Neutral: 0 charge
o
NUCLEUS: DENSE/HEAVY BUT TINY PART OF ATOMFOUND IN CENTER OF AN ATOM
½ Football FieldOuter Edge
of Atom
Nucleus
50 End
Zone
Atomic Nucleus Summary
The nucleus is a dense area at the center of the atom Protons and neutrons are found in the
atomic nucleus
THE ELECTRON
• Found in the electron cloud•Very light: 0 amu•Negative: -1 charge
e-
Electrons
Electrons have a relatively small mass compared to protons and neutrons
Electrons are found far away from the nucleus in an area called the electron cloud
Electrons have a negative charge
How small is an atom?
Atoms are TINY!20 million hydrogen atoms would fit
inside the period at the end of this sentence.
You are made of billions and billions of atoms
http://htwins.net/scale2/
Protons
e-p+ N°
Neutrons Electrons
Positive+1
Neutral0
Negative-1
Nucleus is held together with
nuclear energy
Electron cloud is full of zipping electrons
http://www.youtube.com/watch?v=pV822HfqT44
Please complete the following tableProton Neutron Electron
Location in the Atom
Mass
Charge
Nucleus NucleusElectron
CloudHeavy1amu
Heavy1amu
Very Light 1amu
Positive +1
Neutral 0
Negative -1
ATOMS HAVE A NEUTRAL CHARGE (most of the time……)
When we talk about the atoms of elements on the periodic table, we usually assume they have the same number of electrons as they do protons, giving the atom a neutral charge (+1 and -1 = 0 charge)
So if the atomic number of an atom is 8, how many electrons do we have?
Neutrally charged Atoms will have the same number of electrons as protons
How can I tell which atom is which element?
Every atom of an element has anATOMIC SYMBOL- the letters representing the element Au, Ca etc.
ATOMIC NUMBER – the number of protons + in an atom. Each element has a unique atomic numberExample Carbon’s atomic number is 6, but Boron has an atomic number of 5ATOMIC MASS – the number of protons + plus neutrons 0 in an atom. Example Carbon’s atomic number is 6, but its atomic mass is 12 6 protons and 6 neutrons
N0P+e-
e-
e-
P+P+
What is the atomic number of this atom?
3
Review of Atomic Structure
What is the basic unit of matter? Atom
What are the 3 subatomic particles? Proton, Neutron, Electron
What’s the electrical charge of a proton? Positive (+)
What’s the electrical charge of a neutron? Neutral
What’s the electrical charge of an electron? Negative (-)
N0P+
e-e-
e-
P+P+
REMEMBER WHAT A PROPER ATOM LOOKS LIKE
0
+++
- -
-Name something wrong with this atom 0
+ +
-
+
--
0
What is wrong with this atom?
00
0 0
+
+
-
-+
0
0
What is wrong with this Atom?
Draw an atom CORRECTLY
2 protons, 1 neutron, 2 electrons