To Do With Matter
Scientific Method & Units
Significant Figures
Atoms and the Periodic Table
Mix
100

Which of the following are pure substances?

a) Elements

b) Compounds

c) Homogeneous mixtures

d) Heterogeneous mixtures


Elements

100

What is a hypothesis

A hypothesis is an educated guess or a proposed explanation for a specific phenomenon or problem. It is based on prior knowledge, observations, and reasoning. A hypothesis is testable and serves as a starting point for scientific investigation.

100

Underline the significant digits in each of the following measurements. If any are uncertain place a question mark next to it.

a) 67.00 km

b)0.0013 kg

c) 690 m

d) 209 L

a) 67.00 km (rule 3)

b) 0.0013 kg (rule 1)

c) 690 m (rule 4)

d)209 L (rule 2)


100

Write the symbol for the following element.

a) Hydrogen 

b) Helium

c) Carbon

d) Nitrogen

a) H

b) He

c) C

d) N

100

How many significant figures are in 0.0023040?

Five

200

Classify each of the following an an element, a compound or a mixture.

a) solid iodine (a dark violet solid)

b) a homogeneous combination of sodium and iodine that is a white solid

c) a homogeneous combination of iodine and alcohol, which retains a dark color and the liquid state of the alcohol.

a) Element

b) Compound

c) Mixture

200

How does a theory differ from a hypothesis?

A hypothesis is a proposed explanation for a specific phenomenon or problem, often based on limited evidence. In contrast, a theory is a well-substantiated explanation that has been extensively tested, verified, and supported by a large body of evidence.

200

Round each of the following measurements to three significant digits.

a) 0.0637425

b) 0.637425

c)6.37425

d) 63.7425

e) 6374.25


a) 0.0637

b) 0.637

c) 6.37

d) 63.7

e)6.37x103

200

How many elements are present in the following compounds?

a) OsSO4

b) BN

c) Sc(SCN)3

d) W(CO)6


a) Three

b) Two

c) Four

d) Three


200

How many microgram are in 4.9 kilograms? Give answer in scientific notation

There are 4.9x109 micrograms in 4.9 kilograms.

300

What kind of change - chemical or physical - accompanies each of the following

a)the conversion of two elements to a compound

b) the conversion of two compounds into a solution

c) the combinations of an element and a compound into another compound

d) the conversion of a compound to an element and another compound

a) Chemical change

b) Physical change

c) Chemical change

d) Chemical change

300

Express the following measurements as a decimal value.

a) 7.00 x 10-3 L

b) 7.0 x 10-3 L

c) 7 x 10-3 L

All can be written as 0.007 L

300

Perform the following calculations to the correct significant digits.

a) 219g + 17.39g

b) 6.11mL + 0.012mL

c) 1.102mL + 0.113mL

a) 219 + 17.39 = 236.39 --> 236g

b) 6.11 + 0.012 = 6.122 --> 6.12mL

c) 1.102 + 0.113 = --> 1.215mL

300

Find the number of protons, neutrons, and electrons in an atom of P-31

Protons: 15

Neutrons: (31-15) = 16

Electrons: 15

300

(42.70 + 0.259)/28.4445

1.510

400

What is wrong with the following statement and how might you correct it? "Energy is created when coal is burned."

Due to the Law of Conservation of Energy, energy can neither be created nor destroyed in a physical or chemical reaction. Therefore, a better way to put the statement is "Energy is released when coal is burned." This correctly implies that energy was stored within the coal and is released or transformed upon the combustion of the coal.

400

Convert each of the following numbers to centimeters, and express the answer is scientific notation

a) 6133 mm

b)1.733 m 

c) 20.2 km

a) 6133 mm = 613.3 cm (since there are 10 millimeters in a centimeter) = 6.133 x 10^2 cm

b) 1.733 m = 173.3 cm (since there are 100 centimeters in a meter) = 1.733 x 10^2 cm

c) 20.2 km = 2,020,000 cm (since there are 100,000 centimeters in a kilometer) = 2.02 x 10^6 cm

400

Perform the following calculation to the correct significant digits.

a. (3.08x103g)/(6.912m3)

b. (9.39cm2)/(3.13x10-1cm)

c. (6.93x103cm3)/(30 cm)

a. (3.08x103g)/(6.912m3) --> 4.46x102 g/m3

b. (9.39cm2)/(3.13x10-1cm) --> 30.0 cm

c. (6.93x103cm3)/(30 cm) --> 230 cm2

400

When 47.85g of a cmpound containing only carbon and hydrogen is burned completely in oxygen, it yields 137.55g of CO2 and 107.70g H2O. How much oxygen in grams was used up in the reaction?

(137.55g CO2+107.70g H2O) - 47.85g O2 

= 197.40g O2
400

Which group of the Periodic Table is the element Antimony a member?

15

500

What TWO changes of energy occur when you turn on a flashlight?

1) Chemical energy stored in the battery is changed to electrical energy.

2) The electrical energy is then transformed to light energy at the light bulb.
500

Change 3.50 x 104 cm to

a) meters

b) millimeters

c) kilometers

a) meters: 350 meters. 

b) millimeters: 350,000 millimeters. 

c) kilometers: 0.35 kilometers.

500

Perform the following calculations to the correct number of significant digits.

a. (80.21g-79.93g)/65.22cm3

b. (92.12mL)(0.912g/mL) + 223.03

a) 0.0043 g/cm3

b) 307.0 g

500

Identify the elements: 

a) third period, group 15

b) second period, group 13

c) sixth period, group 18

a) Phosphorous - P

b) Boron - B

c) Radon - Rn

500
Tin boils at 2602 C. What is this temperature in Kelvin?


2875.15

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