1. You need to find the mass of an atom
You need to find the mass of an atom. This neutral atom has 7 negative particles and 8 neutral particles. What is the mass of the atom and what is the name of the element that is being described?
15, nitrogen

2. Which is the correct way to identify an element?
count both neutrons and electrons
count the number of neutrons
count the number of electrons
count the number of protons
Count the protons

3. An atom has seven valence electrons
An atom has seven valence electrons. How will the number of valence electrons influence its chemical properties?
It increases its reactivity with other atoms.

4. Na and Cl bond together because of valence electrons
Na and Cl bond together because of valence electrons. What other elements would also bond with Na, due to similar properties, and form a similar solid substance?
F, Br

5. An element occurs naturally as a solid with a shiny metallic appearance. It is extremely brittle and can be used to create semi-conductors? What is it: a metal or nonmetal or metalloid?
Where is it on the chart?
metalloid

6. Warmup oct 30 2015 3 18 36 6 Iron oxide has the following formula:
Fe2(C2O4)3
How many total carbon atoms are in a basic unit of iron oxide?
How many oxygen's?
How many Iron? 3 6 18 12 36 2 6

7. This is the formula for Caffeine
C8H10N4O2
How would you read it?
One molecule of caffeine contains eight carbon atoms, ten hydrogen atoms, four nitrogen atoms and two oxygen atoms.

8. H2 + O ?
H2 + O H2 O

9. When this reaction is observed, gas bubbles are visible rising to the surface of the liquid hydrogen peroxide and the color of the solution remains clear. The graph shows what happens to the temperature of the liquid as it is monitored over time.
What are the sign(s) that a chemical change has occurred?
Rise in temp
bubbles

10. two liquids are combined After the 2 liquids are combined a white solid appears in the solution. What is the white solid?
precipitate

11. An iron chain on a fence was exposed to air and rain
An iron chain on a fence was exposed to air and rain. What evidence indicated that a chemical reaction between the water, air and iron produced a new substance?
RUST

12. What is happening in the picture that is NOT a chemical change?
Powder dissolves

13. Two liquids of the same temperature are mixed in an open beaker to produce one liquid that has escaping gas bubbles. The gas produced is evidence of what event?
Physical or chemical change?
Chemical changes

14. Which is a chemical change?
It is the same substance but a smaller amount.
It is the same substance but a larger amount.
A new substance is formed.
The substance changes from a liquid to a solid.
A new substance is formed.

15. Which one is ALWAYS a chemical change?
the formation of a gas.
a color change.
the production of new materials.
a change in physical properties.
the production of new materials

16. Which one is conservation of mass?
Matter must first be destroyed in order to be created.
The mass of the products is always less than the mass of the reactants.
The mass of the reactants must always equal the mass of the products.
The mass of the products is always greater than the mass of the reactants.
The mass of the reactants must always equal the mass
of the products.

17. Predict what happens to the chalk in test tube C?
The chalk will be dissolved by the vinegar