Energy & Matter

Fall 2009

Homework for Chapter 11: The Atomic Nature of Matter

· Turn in the questions below on Thursday, November 5 stapled to the questions for chapter 12.

1. What part of an atom contains most of the mass of the atom?

2. What part of an atom occupies most of the volume?

3. One atom has 13 neutrons and 12 protons.

a) What is its atomic number?

b) What is its mass number?

4. About how many atoms would it take to make a line one meter long if they are put next to each other?

5. An atom of polonium has a mass number of 210 and its atomic number is 84. It decays by emitting an alpha particle (2 protons + 2 neutrons) from its nucleus. What are the atomic number and mass number of the new element left after the decay?

6. You have two atoms that are isotopes of the same element; one has 8 neutrons and a mass number of 16. The second has a mass number of 18. How many protons and neutrons does the second atom have?

Homework for Chapter 12: Solids.

· Reading chapter 12 by Tuesday, November 3.

· Turn in the questions below on Thursday, November 5 stapled to questions for chapter 11.

1. You have 1kg of lead, 1kg of aluminum and 1kg of iron. (See page 232 for their densities.)

a) Which one will have the largest volume

b) Which one has the smallest volume?

2. If you squeeze a piece of foam what happens to its

a) Volume

b) Mass

c) Density

3. If a 2N weight stretches a spring by 0.1m, how much will a 1N weight stretch it?

4. If I crush a piece of hard candy (mostly sugar) into many small pieces, what happens to its

a) Volume

b) Mass

c) Density

d) Surface area

5. If a liquid expands when it freezes, will its density increase or decrease?

6. A 100kg rock has a density of 3,000kg/m³. What is its volume?

7. A rectangular parallelepiped has sides of 0.1m, 0.2m and 0.3m. If its mass is 6kg, what is its density?

We will have an Exam after either chapter 12 probably on November 10 or November 17. Bring a Scantron, 882E.