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Chemistry of Life.

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Presentation on theme: "Chemistry of Life."— Presentation transcript:

1 Chemistry of Life

2 Matter Anything that has mass and takes up space. 3 types of matter:
a). Solid b). Liquid c). Gas

3 Solids Any substance that has a definite shape and definite volume.

4 LIQUID Any substance that has a definite volume but not a definite shape. It takes the shape of its container.

5 Gas Any substance that has no definite shape or definite volume.

6 Physical Change Changing the physical properties of a substance without changing the substance itself.

7 Physical Properties The characteristics of a substance that you can observe with the senses. They include: shape color volume texture odor

8 ATOMS The smallest particle of matter that can exist and still have the properties of a particular kind of matter.

9 1. Nucleus – central part of the atom
Atoms are composed of: 1. Nucleus – central part of the atom 2. Protons – positively charged particles (+) 3. Neutrons – uncharged particles 4. Electrons – negatively charged particles (-) electrons protons neutrons orbit

10 Orbits (Energy Levels)
A region around the nucleus in specific energy levels. There are 7 energy levels known to date. 1st energy level holds a maximum of 2 electrons. 2nd energy level holds a maximum of 8 electrons. 3rd energy level holds a maximum of 18 electrons.

11 Elements Substances that are made up entirely of atoms of the same kind and cannot be divided into simpler substances by ordinary chemical means.


13 Symbol – a shorthand method of representing an element.
Atomic Number - # of protons in the nucleus of the element. Atomic Mass Number - # protons + # of neutrons # protons = # of electrons; atoms are electrically neutral

14 How many protons, electrons, and neutrons are found in the following atoms?
Calcium – protons – electrons – neutrons - Iodine – protons – electrons – neutrons - I 53 74 Ca 20 Gold – protons – electrons – neutrons - Au 79 118

15 Molecule – the smallest part of a substance that has all the chemical properties of that substance. Made up of atoms of the same or different kinds of atoms. Compound – matter made up of 2 or more atoms that are chemically combined from different elements. H2O NH3 O2 2NaCl 4H2 CO2 He

16 Chemical (Molecular) Formulas
Shows the kind and number of atoms in a molecule or compound. Ex: H2 - hydrogen gas H – symbol 2 – subscript 2 atoms of Hydrogen 2H2O C6H12O6

17 Chemical Change Always uses or gives off energy
Results in a new substance Ex: H O  2H2O Na Cl  NaCl

18 Mixtures – substances that are combined but not changed chemically
Mixtures – substances that are combined but not changed chemically. Ex: cereal & milk vegetable salad How could a mixture of salt and water be separated? 2 types: a) homogeneous – one in which the substances are evenly distributed. b) heterogeneous – the substances are not evenly distributed.

19 Mixtures Solution – a mixture that is formed when the molecules of one substance mix evenly with those of another substance. ex: Kool-Aid lemonade Suspension – a heterogeneous mixture containing particles distributed with a liquid, gas, or solid. ex: soil & water RBC & blood Colloid – a mixture composed of particles dispersed in a medium ex: gelatin (partly solid & partly liquid) How is fog a colloid?

20 Acids & Bases Acid – a chemical that produces hydrogen ions in a water solution. Ex: HCl H2SO4 Base – a chemical that produces hydroxide ions in a water solution. Ex: NaOH

21 pH pH scale – scale for measuring how acidic or basic various solutions are. Ranges from 0 to 14 a solution w/a pH of 7 is neutral a solution w/a pH below 7 (0 to 6.9) is acidic a solution w/a pH above 7 (7.1 to 14) is basic Ex: stomach acid vinegar milk blood soap 1 3 6.5 7.3 10

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