Question

Science Review. Help???

Answer 1

1. Of the following, the only change that is an example of a chemical change is —

A. water evaporating from a puddle
B. an iron nail rusting and turning an orange color
C. a piece of paper being cut into smaller pieces
D. a stick being broken in half




2. All of the following involve chemical changes except —

A. an ice cube disappearing after being placed in a glass of water
B. frying an egg
C. a piece of silver jewelry tarnishing
D. a green coating forming on a copper statue



3. A section of the Periodic Table of the Elements is shown. Based on the positions of the elements, the two elements that have the most similar chemical properties are —

A. calcium and scandium
B. calcium and titanium
C. titanium and vanadium
D. magnesium and calcium




4. One property used to broadly classify elements is malleability. If a substance is malleable, it can be hammered, shaped, and flattened without shattering. Which group of elements has this property?

A. Metals
B. Metalloids
C. Nonmetals
D. Noble gases





5. Which best describes the similarities among elements included in the same column of the periodic table?

A. They have the same state at room temperature.
B. They have the same number of protons.
C. They have the same number of electrons.
D. They have similar chemical properties.







6. This illustration shows a section of a periodic table. What property do the elements touching the dark zigzag line have in common?

A. They are gases.
B. They have properties of metals and nonmetals.
C. They are all metals.
D. They have the same properties as the noble gases in the last column.




7. Which compound is made up of three elements?

A. H2O2
B. CaCl2
C. HNO3
D. Na2O










8. Which of the following is a compound?

A. O2
B. C60
C. CO
D. Cu




9. Why is the substance shown in this illustration a compound?

A. This substance is made up of atoms.
B. This substance contains oxygen.
C. This substance contains two different elements that are combined.
D. This substance is carbon dioxide, CO2.







10. How does this illustration show an example of a chemical change?

A. Energy is released as heat.
B. The candle gets shorter.
C. The wax drips as the candle melts.
D. As the candle burns, new substances are made.

Answer 2

@whpalmer4

Answer 3

@aaronq

Answer 4

i believe it is 1-B 2-C 3-A 4-A 5-B 6-B 7-C 8-D for 9 and 10 i cant answer because i cant see the illustration it is asking about.

Answer 5

Remember that anything that is a chemical change is changing the substance, while anything exhibiting a physical change has to do with its physical properties, and is not changing substance.

Elements within the same group on the Periodic Table have the same number of Valance Electrons.

Remember that in a chemical equation each new element is introduced with a capital letter, and that compounds are two elements together.