Hw packet 8-10 review for TEST

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Transcript Hw packet 8-10 review for TEST

THE FOLLOWING SLIDES ARE REVIEW OF HOMEWORK 8-10 (PACKET)

1) The four diagrams below model the results of

mixing

atoms of different substances. Each atom is represented by a different symbol. Which diagram correctly models a chemical change?

a) b) c) d)

2) The table below shows the chemical symbols for common elements.

Based on the information in the table, which of the 4 substances below is a compound?

a) CO b) He c) Si d) Fe

3) The diagram below shows a rock sample and an identification key. This rock sample is an example of a) an element c) heterogeneous mixture b) compound d) homogeneous mixture

4) Some common substances and their chemical formulas are listed in the chart below Which of these substances are elements?

a) hydrochloric acid c) oxygen and helium b) carbon dioxide and water d) water and oxygen

5) The illustration below shows a solid metal ball and a ring before and after heat is applied to the metal ball. Before heat is applied, the metal ball passes easily through the ring. After heat is applied, the metal ball does

not

pass through the ring.

What evidence shows that a physical change took place in the metal ball? Ans: The ball would not pass through the ring anymore after it was heated because its size changed.

***6) Magnets A and B are of equal magnetic strength. In which position will the magnets A and B have the greatest attractive force toward each other?

a) c) b) d)

7) A chemical property of a mineral is evident if the mineral a) breaks easily when struck with a hammer b) bubbles when acid is placed on it c) is easily scratched by a fingernail d) reflects light from its surface

8) Equal–sized pieces of aluminum were placed in test tubes containing equal volumes of acid, at different temperatures. The temperature of the acid is test tube A is 5 o C. The temperature of the acid in test tube B is 20 o C. What observation would indicate that a chemical reaction is taking place in the test tubes? Ans: Bubbles start to form

10) Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride is formed and hydrogen gas is released. This is an example of a) physical change b) chemical reaction c) homogeneous mixture d) heterogeneous mixture 11) Which one of the following characteristics represents a chemical property?

a) Reactivity d) Color b) Malleability c) Solubility e) Melting Point

12) Sand and iron particles that a similar in size and color are mixed together in a beaker. What would be the best method in separating the particles?

a) Use tweezers to separate them b) Use a magnet to separate them c) Add water to separate the mixture d) Pour the mixture into a filter 13) Which action forms a different chemical substance?

a) crushing a rock b) burning a piece of wood c) mixing salt and pepper d) melting an ice cube

14) A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change?

a) The baseball strikes the roof dents c) The paint cracks and chips b) The roof of the car d) The exposed metal rusts

15) List one observation that shows a chemical change is occurring in the diagram.

Ans: Bubbles start to form

16) Identify the soluble material, the insoluble material, and the solvent.

Soluble Salt Sand Solvent: ________________________________________________

.

17) Explain why the contents of the flask in Figure B are classified as a mixture.

Ans: The substances are combined with NO chemical change

.

18) Explain why only solid salt particles remain in the flask in figure C.

Ans: The water evaporated (liquid to gas)

***25) The flask and its contents had a mass of 120 grams before the experiment and a mass of 120 grams after the experiment. Which conclusion can best be made from these measurements?

a) a phase change took place c) Matter was conserved b) Energy was destroyed d) New elements were formed

26) The chemical change that occurred in the flask is most similar to a) burning a piece of coal b) freezing water in a container c) breaking a piece of wood into many pieces d) bending a wire to form a hook

Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period.

Definitions: 1) Atom: lego blocks of all matter 2) Matter: anything that takes up space 3) Element: type of atom 4) Molecule: 2 or more atoms connected at electrons 5) Compound Molecule: molecule with different elements 6) Chemical Reaction (Change): when new molecules are formed 7) Fusion: nuclei of more than one atom combine to form a new element

Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period.

Definitions: 8) Reactants: molecules/atoms you begin with (left of arrow) 9) Products: molecules/atoms you end with (right of arrow) 10) Physical Change: change in physical characteristic but NO new molecules formed 11) Coefficient: Big # before molecule. Tells am’t of molecules 12) Subscript: lower # in a molecular formula. Tells am’t of atoms 13) Mixture: physical combination of things but NO chemical change

Create flashcards for the following words. Get into pairs and quiz each other. Prepare for quiz toward end of the period.

Definitions: 14) Heterogeneous Mixture: mixture where you can see the different substances 15) Homogeneous Mixture: mixture where everything looks the same 16) Solution: homogeneous mixture where something dissolves 17) Soluble: Can dissolve 18) Insoluble: Can not dissolve 19) Solute: The thing dissolving 20) Solvent: the thing that a substance dissolves in

Additional Vocabulary: 21) Temperature 22)State of matter 22) Phase Change 23) Condensation 24) Evaporation 25) Sublimation 25) Boiling point 26)Melting point