Chemistry-Chemical Reactions

Question 1

1. What is the difference between atoms, elements, molecules, compounds, mixtures, and pure substances?

Answer 1

Atom: single part Element: two or more of a single atom Molecule: two or more of a single element, Compound: two or more of DIFFERENT elements bonded together Mixture: two or more of DIFFERENT substances NOT bonded together Pure Substances: ONLY ONE TYPE OF ATOM

Question 2

2. What information is found within a chemical formula?

Answer 2

elements have been combined (REACTANTS) to form a new substance (PRODUCT)

Question 3

3. What evidence supports that a chemical change has occurred?

Answer 3

Possible change in: Color, Odor, Temperature

Question 4

4. Be able to describe how the properties of the products and reactants might differ?

Answer 4

the properties of the products and reactants might differ

Question 5

5. What is a precipitate?

Answer 5

A final product or by-product of a chemical reaction when a liquid becomes a solid or a gas becomes a liquid

Question 6

6. What are the parts of a chemical equation?

Answer 6

Reactants to the left of the equation; Products to the right side of the equation

Question 7

7. What is a MSDS and what information does it contain?

Answer 7

Material Safety Data Sheet: All important information about chemicals

Question 8

8. What information is given in the MSDS concerning the proper disposal, reuse or recycling of materials?

Answer 8

MSDS will tell you exactly how a chemical is suppose to be disposed of, but always consult your teacher for more specific directions.

Question 9

9. How can you tell if an equation is balanced?

Answer 9

There are equal amounts of each type of ATOM and Element on both sides of the arrow sign

Question 10

10. Be able to count the number of atoms in the reactants and products to determine if the equation is balanced.

Answer 10

See simulations

Question 11

11. What is a subscript? How is it used to determine the number of atoms in a substance?

Answer 11

Number to the bottom right side of a specific element symbol telling us how many of that particular/specific atom there are. EX: O3

Question 12

12. What is a coefficient? How is it used to count the number of atoms in a substance?

Answer 12

A number to the LEFT of a set of element symbols. This number tells you how many SETS of that element/atom there are in the chemical equation EX: 3H2O = H2O , H2O, H2O

Question 13

13. What is the Law of Conservation of Mass?

Answer 13

Matter can neither be created or destroyed it is just recycled or reattributed

Question 14

14. How does a balanced equation relate to the Law of Conservation of Mass?

Answer 14

NO NEW ATOMS/ELEMENTS ARE CREATED OR DESTROYED