1. Name: ____________________ Integrated Science 4A
Unit 1- The Atom
Name: ____________________
Integrated Science 4A

2. Chemistry What is chemistry?
Chemistry is defined as the study of matter.
Chemistry is vital to our every day lives and without it, we wouldn’t have medicines, food, clothing, and everything else around us. There would be no life without chemistry.

3. What’s an atom?
Atoms make up the matter that is around us. Atoms are the basic building blocks of matter. DEFINITION: Atoms are the smallest particle of an element that has all of the element’s chemical properties.
Examples: stars, steel, and ice cream.
Only a few kinds of atoms combine in different ways to produce all the countless substances on earth.

4. Subatomic particles Proton +1 1 Nucleus Neutron Electron -1
Charge
Mass
Location of Atom
Proton +1 1
Nucleus
Neutron
Electron -1
Outside nucleus

5. Nucleus Every atom has a nucleus in the center.
The nucleus consists of the protons & neutrons. These atoms are bound together.
Electrons surround the nucleus of an atom.

6. Atomic Number
Atoms differ from one another because of their proton number, otherwise known as the atomic number.
Atomic Number: number of protons.
All the elements in the periodic table are listed according to the element’s increasing atomic number (from left to right).
For example: hydrogen’s atomic number is ___.
Carbon (C) = ______ Nitrogen (N) = ______
Every atom also has it’s own abbreviation on the periodic table called a symbol.

7. Atomic Number= # that shows the # of protons in an element.
How to Calculate: # of PROTONS
Atomic Mass= mass of an element’s atoms on the periodic table as an average of its isotopes.
How to Calculate: PROTONS+NEUTRONS
Mass Number= total # of nucleons in an atom’s nucleus
How to Calculate # of neutrons= Atomic Mass - Atomic #

8. Can you find the following element’s atomic number?
Oxygen (O) = _____ Potassium (K): ______
Helium (He)= _____ Copper (Cu)= _____

9. What’s an element?
An element is any material that is made up of only one type of atom. Elements are found on the periodic table.
Examples:
Pure gold- only contains gold atom.
Nitrogen gas-only contains nitrogen atoms.

10. Ions Ions = elements that GAIN or LOSE one of more electrons.
Ions are when an atom has an unequal number of p+ and e-
Remember – a stable atom has a neutral overall charge due its equal number of p+ and e-
When an atom loses or gains an e-, its charge changes
Loss of e- means a + charge; gaining an e- means a – charge for the atom

11. Examples of Ions Red – Protons Blue- Electrons Yellow- Neutrons
Hydrogen 1 +1
Carbon 6 +4
Lithuim 3 4 -1
Beryllium 5 -2

13. Isotopes An element is defined by the number of protons it has.
Is it the same element if you add or
remove NEUTRONS?
YES
BUT It is called an ISOTOPE!!
Isotope- atoms with the same number of PROTONS, but differing numbers of NEUTRONS. Isotopes are different forms of a single element.

14. Isotope Examples

15. How to Find # of Neutrons in Isotopes
Find the number of protons, neutrons, and electrons.
Subtract the mass number – atomic number to find the number of neutrons.
Remember: number of electrons is the same as the number of protons.
Carbon-14  has _____ neutrons
Carbon-12  has _____ neutrons 
Mass number

16. Determining the Average Atomic Mass
(Mass of Isotope 1)(% Abundance of Isotope 1) +
(Mass of Isotope 2)(% Abundance of Isotope 2) +
(Mass of Isotope 3)(% Abundance of Isotope 3) +
(Mass of Isotope ∞)(% Abundance of Isotope ∞)

17. Example N 14 and N 15 have a atomic mass of 14.007.
What are the percentages of abundance?
End of Notes!

18. Ions Gain electrons =element gets a _____________ charge.
Gain electrons means there are MORE electrons than protons.
Lose electrons = element gets a ______________ charge
Lose electrons mean there are LESS electrons than protons.

19. For example, the element sodium (Na) has 11 electrons—this is NOT balanced and is not a happy element—it wants to LOSE an electron.
So it finds an element that is also unhappy. Chlorine (Cl) has 17 electrons, it is unhappy, so it wants to GAIN an electron.
Na gives up it’s electron to Cl; Cl gains that electron and both elements now become ions.

20. Example
Li-1 has gained an electron, meaning there is one more negative charge than positive ones
It has 3 p+ and 4 e-
Li+1 has lost an electron, meaning there is one more positive charge than negative ones
It has 3 p+ and 2 e-
REMEMBER: The # of p+ DO NOT CHANGE
Only the number of neutrons (isotope) and electrons change!!!

21. How to Represent Atoms and Isotopes
By name:
(Element name)-Mass#
Hydrogen-2
Chlorine-35
By symbol:
****Go back to notes from Monday!