1. Atoms, Molecules, Compounds

2. All matter is made of one or more elements.
Elements are pure substances that cannot be broken down by any chemical or physical means.
Element

3. Elements A substance consisting of a single type of atom.
It cannot be broken down into different kinds of matter.

4. Atoms The basic component of all matter.
The atom is the smallest particle of an element that has all of the chemical properties of that element.
Atoms consist of a nucleus of protons and neutrons surrounded by electrons. 1

5. Atomic Structure
Atoms are composed of 3 subatomic particles called protons, neutrons and electrons.
The center of the atom is called the nucleus. It contains protons and neutrons.

6. Atomic Structure Circling around the nucleus is 1 or more electrons.
Atoms are different from each other because each element’s atoms have different #s of the subatomic particles.

8. The electron is found moving around the outside of the nucleus.
Electrons
The electron is found moving around the outside of the nucleus.
The electron has a (-) electric charge.

9. Electrons
The e- has a mass of amu. (The mass of the electron is so small compared to the proton and neutron that it is ignored.)

10. Protons
Protons are located in the center core of the atom called the nucleus.
Protons have a positive electric charge (+1)
Protons (p+) have a mass of 1 amu (atomic mass units).

11. Structure / Parts of the Helium Atom
Electron
Neutron
Proton

12. Neutrons Neutrons are also located in the nucleus.
Neutrons are electrically neutral. They do not have a charge.
Neutrons (n0) have a mass of 1 amu.

13. Periodic Table

14. AMU = protons + neutrons + electrons

15. Periodic Table
The periodic table gives the following information about each element and its atoms.
Atomic Number
Atomic Mass
Element Symbol

16. Sample Periodic Table

17. Using the Periodic Table
The symbol is an abbreviation for the name of each element. It’s either 1 or 2 letters with the 1st letter capitalized.
The atomic number is the smaller of the 2 numbers. This number tells us the number of protons and the number of electrons in the atom.

18. The atomic mass # is the sum of the protons, neutrons, and electrons.
This number is used to find the number of neutrons.

19. Neutrons =
Atomic mass (rounded) – atomic number
A.M. – A.N. = n0

20. Combinations of Elements: Compounds
A substance formed from two or more elements, with a fixed ratio determining the composition.
The elements lose their individual chemical properties and the compound has new properties.

21. Molecules
Compound of two or more atoms, the smallest unit of chemical compounds.
The smallest particle of a substance that has all of the physical and chemical properties of that substance.

22. Combinations of Elements: Mixtures
A substance consisting of two or more substances mixed together.
Mixtures can usually be separated by mechanical means.
Two or more substances mixed together in such a way that each remains unchanged.

23. Formulas
The formula which identifies the atoms and the number of each type of atom in the molecules of a compound.
The number and types of atoms in a molecule.
Glucose -C6H12O6

24. Elements in the compound
Formulas
6C6H12O6
Carbon Hydrogen Oxygen
Elements in the compound

25. Number of atoms of each element in a molecule of the compound:
Formulas: Subscripts
6C6H12O6
Number of atoms of each element in a molecule of the compound:
Carbon = Hydrogen = Oxygen = 6

26. Formulas: Coefficients
6C6H12O6
Number of molecules =
6 molecules of glucose