2 1. What is the mathematical formula for density? Mass divided by Volume
3 2. Object X has a mass of 1g and a volume of 1ml 2. Object X has a mass of 1g and a volume of 1ml. Object Y has a mass of 5g and a volume of 5ml. Which object has a greater density?They both have the same1/1=15/5=1
4 3. Explain what elements make table salt? The elements sodium and chlorine are chemically combined to create table salt. One sodium atom is combined with one chlorine atom.
5 4. Explain what elements make water? Hydrogen and oxygen are chemically combined to form water. Two hydrogen atoms are combined with a single oxygen atom
6 5. What is a substance that dissolves in water called? Solute
7 6. 2 ml of lead has a mass of 20g, what is the density of lead? 20/2=10g/ml
8 7. The density of silver is 10. 49 g/cm3 7. The density of silver is g/cm3. If a sample of pure silver has a volume of cm3, what would the mass?Mass = volume x density12.993x10.49=136.3g
9 8. Pure gold has a density of 19. 32 g/cm3 8. Pure gold has a density of g/cm3. How large would a piece of gold be if it had a mass of g?Volume = mass/density318.97/19.32 = 18.96cm3
10 9. The density of lead is 11. 342 g/mL 9. The density of lead is g/mL. What would be the volume of a g sample of this metal?Volume= mass/density200/ = 17.63ml
11 10. The mass of a toy spoon is 7. 5 grams, and its volume is 3. 2 ml 10. The mass of a toy spoon is 7.5 grams, and its volume is 3.2 ml. What is the density of the toy spoon?Mass/volume7.5/3.2 = 2.3g/ml
12 11. A mechanical pencil has the density of 3 grams per cubic centimeter. The volume of the pencil is 15.8 cubic centimeters. What is the mass of the pencil?Mass = volume X density15.8x3 = 47.4g
13 12. Can you easily separate a solution by filtration? Explain. You cannot easily separate a solution by filtration. The solute is dissolved. You have to evaporate out the solvent.
14 13. What is the temperature at which a solid changes into a liquid is known as? Freezing point
15 Label the following as Chemical or Physical Change Label the following as Chemical or Physical Change. (remember: Chemical cannot be changed back)14. Water being frozen into ice cubes P15. Water vapor rising from the surface of a hot drink P16. Paper being crumpled into a ball P17. Smoke coming from an automobile exhaust pipe C
16 18. Adam wants to know if red or green apples turn brown faster when exposed to air. He slices one red apple and one green apple in half. He leaves the exposed surfaces facing upward. After ten minutes, he records the observations shown in the chart below.What should Adam's next step be?Adam should complete more trials. He should check the apple more often to look for a change sooner.
17 19. An iron door handle on an outdoor shed has reacted with oxygen from the atmosphere. Which of these observations indicates that a reaction has occurred?The handle is covered with scratches.The handle is spotted with rust.The handle is bent out of shape.The handle is cool to the touch.
18 20. Explain how you could separate the salt out of the saltwater mixture? You have to either let all of the water evaporate out or you can boil the water until all has boiled out and you have only salt remaining.