We will meet in the computer lab,
Room 301, tomorrow, the 17 th.

PHYSICAL SCIENCES o Benchmark A: Describe that matter is made of minute particles called atoms and atoms are comprised of even smaller components.
Explain the structure and properties of atoms.

 The smallest particles of matter are called atoms.
Neutrons have no charge
Protons have a positive charge
Electrons have a negative charge

 If an atom loses an electron, it becomes positive.
 If an atom gains an electron, it becomes negative.
 Positive and negative charged atoms are called ions.

 All the different types of atoms are called elements and are organized onto the periodic table.
 Each element has a different number of protons/electrons.
 All atoms of the same type of element contain the same number of protons. This is called the atomic number.
 The atomic mass is shown at the bottom of the element; it is a combination of the weight of protons and neutrons in that element

 The same type of element will always have the same number of protons, but that element can differ in the number of neutrons. This is called an isotope; each isotope of an element has a different atomic mass
Example: Carbon-12
Carbon-14

 Periodic Table is organized to relate similar properties together o o o
Horizontal rows are called periods and indicate how many energy levels (shells) the elements have (e.g.
Elements in period two have two energy shells to fill)
Vertical columns are called groups or families and show how many electrons are in the outermost energy shell
The table is usually color-coded to show what physical state the elements are in

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