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CHAPTER 1 I. DESCRIBING MATTER.

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Presentation on theme: "CHAPTER 1 I. DESCRIBING MATTER."— Presentation transcript:

1 CHAPTER 1 I. DESCRIBING MATTER

2 HINT: Vocabulary words are this color!
Put them into your vocabulary section of you spiral as we go.

3 A. MATTER - anything that has mass & volume.
1. Properties (characteristics) of matter - used to identify substances * ex.s - flammability, color, shape, texture, temperature 2. CHEMISTRY - the study of the properties of matter & how matter changes

4 B. KINDS OF MATTER 1. ELEMENTS -substances that cannot be broken down into any other substance by chemical or physical means. - building blocks of matter - all matter is composed of elements - made up of ATOMS - each element has its own symbol - can exist in combined or uncombined form

5 Copper - Cu is copper’s symbol

6 Mercury - Hg

7 Gold - Au

8 Sulfur - S

9 Uranium - U

10 2. COMPOUNDS - substances made of 2 or more elements chemically combined in a specific ratio & having their own specific properties. * ex.s - CO2 carbon dioxide - H2O water - H2O2 hydrogen peroxide

11 a. FORMULA - H2O - this is a formula.
*The formula: - uses symbols to identify which elements are present. - shows the ratio of elements in a compound.

12 3. MIXTURES - 2 or more substances that are mixed but NOT chemically combined.
Most matter found in the environment occurs in mixtures! Mixtures differ from compounds in 2 ways: 1. Substances keep individual properties ex. - soil, salt water 2. Parts of mixtures do not come in specific ratios

13 C. CHANGES IN MATTER 1. Physical change - a change that alters the form or appearance of a material but does not make the material into a new substance. Ex.s - chopping wood, bending wire, painting a car, ice melting to water

14 What is the difference between these two statues? Is this physical or chemical ?

15 2. CHEMICAL CHANGE A change in matter that produces new substances.
Substance contains the same elements but atoms are rearranged in new combinations. Ex.s - rusting, burning, oxidation

16 Burning trees are chemically changed into
other substances like carbon and ash.

17 II. MEASURING MATTER - Sect. 2
A. MASS - the amount of matter in an object. Units of Mass - grams (or kilograms)

18 ARE MASS AND WEIGHT THE SAME??
NO!! REMEMBER - mass is the amount of matter in an object. Weight is the affect of gravity on an object’s mass!

19 B. Volume - the amount of space an object takes up.
Volume = length x width x height Units of volume - liter - cubic centimeter

20 C. Length - distance Units of length - meters

21 D. Density - how much mass is contained in a given volume.
To calculate the density of an object, divide its mass by its volume. D = M/V Units of density - g/cm3

22 Everything’s density is compared to water.
Water’s density is 1.0 g/cm3 So if an object has a density of 3.5 g/cm3, does it sink or float? How about an object with a density of 0.47 g/cm3?

23

24 III. PARTICLES OF MATTER
A. ATOMS - the smallest possible piece of an element with all the properties of that element. 1. 1st thought of by Democritus (440 b.c.e.) an ancient Greek a. atomos - “uncuttable”

25 2. Dalton - (1802) British teacher formed ideas through experiments
DALTON’S IDEAS: formed the basis of our modern understanding of atoms 1. Atoms can’t be broken into smaller pieces. 2. Atoms of different elements are different.

26 4. Atoms of each element have a unique mass.
3. Atoms of 2 or more elements can combine to form compounds. 4. Atoms of each element have a unique mass. 5. The masses of the elements in a compound are always in a constant ratio.

27 B. Atoms today 1. Atoms are very small
number of atoms in 1 grain of sand = (more than all the grains of sand on the whole beach!!) There are 2,000 billion oxygen atoms in drop of water 2,000,000,000,000,000,000,000 & 4,000 billion hydrogen atoms !!!

28 Imagine a marble in the center of this stadium - It would be the atom’s nucleus (99.9% of an atom’s mass) the rest the electron cloud.

29

30 C. Atoms & Molecules 1. Chemical bonds - the force that holds atoms together to form molecules. MOLECULE - the combination of 2 or more atoms that are bonded together. Ex.’s - H2O = 1 molecule of water O2 = 1 molecule of the oxygen we breathe C2H4O2 = 1 molecule of a simple sugar

31

32 Some molecules can be huge. They may
contain millions of atoms.

33 The DNA molecule

34 IV. Elements From Earth A. (Integrating Earth Sci.)
1. Gold (Au) g/cm3 a. Pyrite (Fool’s Gold) 5.0 g/cm3 HOW WOULD THIS BE USEFUL TO KNOW? b. Gold’s density allows it to be “panned”

35 2. Compounds in Nature a. Most elements are found in compounds
ex.s - copper compounds, iron ores 1. Ores are rocks that contain metal or other economically useful materials. 2. To separate elements from the compounds they are found in, requires a chemical reaction.

36 Electrolysis - “electric cutting”
A chemical reaction & a way of breaking apart a compound. - copper Heat may also be used to chemically break apart compounds. - iron forges (blast furnaces)


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