The document discusses the basic concepts of chemistry including atoms, elements, compounds, and mixtures. Atoms are the building blocks of elements, and elements are pure substances made of only one type of atom. Compounds are pure substances made of two or more elements chemically bonded together, while mixtures are combinations of elements or compounds that are not chemically bonded and can be separated.
8. What are atoms? -Atoms are the basic building blocks of matter that make up everyday objects. -A desk, the air, even you are made up of atoms! -There are 90 naturally occurring kinds of atoms.
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18. ATOMIC NUMBER and MASS NUMBER Atomic number 12 6 C Mass number Number of protons (+) Protons + Neutrons
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21. Magnesium Atoms Oxygen Atoms Molecules of magnesium oxide Summary element element compound atom atom molecule
22. Compounds are pure substances made of 2 or more elements chemically BONDED together.
24. Li + + H 2 O LiOH + H 2 If lithium is added to water , lithium reacts with the water molecule forming lithium hydroxide and hydrogen gas . Alkali
25. Count the atoms for each element that makes up the following compounds: Example: Water – H 2 O 2 atoms of Hydrogen 1 atom of oxygen COUNTING ATOMS
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27. A MIXTURE is a material made up of 2+ substances which may be elements or compounds that are NOT CHEMICALLY BONDED.