Chemistry Content Review

Unit 1 (Intro)

100

The SI unit for electric current.

What is the Ampere?

200

Burning a candle is a ____________ change while melting wax is a _____________ change.

Chemical; physical

300

Convert the following to scientific notation:

0.000456

4.56 x 10^-4

400

What are the significant figures in the following number:

0045060.0

0045060.0

500

Write the following value using the correct SI units in scientific notation.

25000 nm

2.5 x 10^-5 m

Unit 2 (States of Matter)

100

What are the three phases of matter?

solid, liquid, gas

200

What is it called when a solid becomes a liquid?

Melting

300

What three phase changes are Endothermic?

melting, boiling (evaporation), sublimation

400

What phase has a fixed volume and variable shape?

liquid

500

On a heating curve, where does the potential energy increase?

phase changes (the flat lines)

Unit 3 (Atomic Structure)

100

What charge does an electron have?

negative

200

What is the average atomic mass for mercury?

200.59

300

How many protons are in an atom of Vanadium?

23

400

How many neutrons are in bromine-81?

46

500

Look at Boron on your periodic table. It has two isotopes, boron-10 and boron-11. Based on the average atomic mass, decide which you think is MOST common and calculate the number of neutrons there should be in MOST boron atoms.

6

Unit 4 Equations

100

What type of decay produces a particle with a +2 charge?

alpha

200

What type of nuclear reaction is shown below?

²⁵²₉₉Es + ¹₀n --> ⁵⁰₂₁Sc + ²⁰⁰₇₈Pt + 3¹₀n

fission

300

As the atomic number goes up, the neutron to proton ratio does as well. What is the maximum it reaches?

1.5 neutrons:1 proton

400

Balance the following equation:

²⁰⁸₈₄Po --> __________ + ⁴₂He

²⁰⁴₈₂Pb

500

Balance the following equation.

¹⁵₇N + ⁶₃Li --> ______ + 2¹₀n

¹⁹₁₀Ne

Unit 4 Half-Life

100

Half-life is the amount of time it takes for a radioactive sample to decrease its mass by how much?

half (50%)

200

Half-life is a ______________ for a given isotope.

constant

300

If the half-life of a substance is 14.7 years, and you start off with 98 grams of the substance, how much will remain after THREE half-lives?

12.25 g

400

If the half-life of a substance is 113 years, how many half lives will it take for a 45 g sample to decay into 1.40625 g?

5

500

If the half-life of a substance is 790 years, how long in years will it take for a 18 g sample to decay into 1.125 g?

3,160 years