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The Chemical Nature of Matter- Study Guide
I.
What is matter?
A. Matter is made up of particles too small to be seen called atoms.
1. Atoms have mass AND maintain properties of the element(s).
2. Atoms are made up of subatomic particles (creates mass): protons, neutrons & electrons
II. How do we classify or organize how we think about matter?
A. Matter is categorized as:
*element (pure substance or one kind of atom)
*compound (more than one element that can’t be separated)
* mixture (heterogeneous or homogeneous)
B. Matter can be found in one of three states (solid, liquid or gas).
III. What are the properties used to identify matter?
A. Physical properties can be observed without changing the type of matter
1. melting point (temp solid to liquid- example ice to water at 32)
2. boiling point (liquid to gas- example water to vapor at 212)
3. density (comparing mass to a particular volume)
4. color (even the absence of color is a physical property
B. Chemical properties are when matter reacts or do not react chemically with one another (change)
1. Ability to rust, burn, bonds to hydrogen, etc…
IV. How is the periodic table organized?
A. Each squareAtomic number -# of protons (electrons too!)
11
Na
Chemical name
Atomic Mass
Chemical Symbol
Sodium
22.990
B. Rows- called periods (just like you have 7 class periods) ----------------C. Columns- called groups/families (similar properties)
D. The “zig-zag” separates the metal and nonmetals.
1. Metals- most plentiful, on LEFT
2. Non metals- on RIGHT
V. How do metals and nonmetals compare?
A. Physical properties of metals (Na, Ca, Fe, Al)
1. Luster (shiny?) Conductor (electricity)? Malleable (hammered shapes)? Ductile (pulled into wire)?
High density (heavy for size)?
B. Physical properties for nonmetals (Cl, O, S, I)
1. Dull, nonconductor, brittle
VI. Why/how are chemical symbols & formulas used?
A. To show the component parts of a substance. More than one symbol makes up a formula.
B. Symbol- first letter is always capitalized and number of atoms is the little #.
1. NaCl (salt)
2. H₂O (water)
3. C₆H₁₂O₆ (simple sugar)
4. O₂ (oxygen)
5. CO₂ (carbon dioxide)
6. N₂ (nitrogen)
VII. How does matter change?
A. Physical CHANGES…. Composition remains the SAME.
1. Change in size or shape like tearing, cutting, and dissolving
*stretching rubber band, denting metal, making Kool-Aid
2. Change in state of matter.
*Melting of ice cream, hardening of melted wax, evaporating of water from clothes.
B. Chemical CHANGES……. Formation of NEW substance(s)
1. Temperature change (ex- wood burns to ashes) NOT include all “warming/cooling”- pool water
2. Precipitate forms (two solutions form solid substance) example chalk from calcium carbonate
3. Gas forms- look for bubbles (ex-vinegar & baking soda) NOT all bubbles- boiling water
4. Color change (ex-brown apple, iron rusting, clothes bleached, marshmallows black) NOT include
adding food coloring
VIII.
Why do we need to know about reactants and products?
A. A chemical equation represents a chemical reaction has occurred.
B. LEFT of arrow shows what has been broken apart or combined REACTANTS
C. RIGHT of arrow shows new substance PRODUCT
1.
Combine
yields/makes
new substance
2H₂ + O₂
→
2H₂O
IX. How do we prove that matter is neither created nor destroyed?
A. Using chemical equations and counting atoms on either side, they must be equal. This supports the law
of conservation of matter. Total mass (reactants) must equal total mass (products). BALANCED
EQUATIONS.
B. Little numbers to the right of symbol are subscripts; big numbers to the left are coefficients.
C. Is the equation below balanced? ****multiply co-efficient **** add if needed****count atoms****
Fe₂O₃
+
3H₂
→
2Fe
+
3H₂O
(Does it support the law?)
X. What indicates an acid or base?
A. Acid- sour taste, reaction to some metals (lemons, inside your stomach)
B. Base- bitter, slippery (bleach, Tums, etc…)
C. pH scale
1. Range between 0 and 14
*0 acidic
*7 neutral
*14 basic
2. Litmus Paper
*If testing for an acid use blue litmus paper… it will turn red.
*If testing for a base use blue litmus paper… it will turn blue.
3. Phenolphthalein
*Turns a bright pink in presence of a base.