Which of the following cannot be tested by science?
How emotion affects the quality of a painting
What part of the scientific method involves controlling variables while testing a hypothesis?
Conducting an experiment
Which of the following could be considered a scientific statement?
I observed that bees prefer red flowers.
A scientist conducts an experiment to determine how the CO2 levels in ocean water affect the number of plants that can grow in the ocean. What is the dependent variable?
Number of plants.
Carlos is trying to determine how music affects the growth of bean plants. He hypothesizes that classical music will cause a plant to grow at a higher rate than no music or rap music. He grows nine bean plants in similar lighting, temperature, and soil conditions. Three are exposed to classical music 24 hours a day, three are exposed to rap music 24 hours a day, and three are grown in complete silence. Carlos measures the growth of the plants every day and finds that the plants all seem to have the same rate of growth.
What is missing from Carlos's scientific investigation?
Research on what other scientists have observed and investigated on this topic
Which of the following is not a characteristic of reliable science?
Paid sponsorship by a company
Which statement is not true about the field of science?
It is consistent and does not need to change with new discoveries.
If a question cannot be tested and observed, it cannot be answered with science.
True
Read the two questions.
Question 1: Should acid precipitation be a concern for the new age environmentalist?
Question 2: Does acid precipitation in forests affect the reproduction rate in birds?
Use complete sentences to explain whether both questions can be answered by science or not. Be sure to explain why for each question.
Question 1: This question cannot be answered by science because it cannot be measured using the scientific method, which means that it cannot be answered by science.
Question 2: This question can be answered using the scientific method and a scientific experiment, which means that it can be answered by science.
Which of the following is a valid conversion factor?
1 kg/1000 g
How many kilograms are in a 50.0-pound luggage bag?
Use 1 pound = 0.45 kg
22.5 kg
Which of the following units would you use to describe the amount of air in a propane tank?
Gallon
The kilogram is the SI unit for mass.
True
73 m is equal to ___ dm.
730
If you calculated 41.0 ÷ 0.302, how many significant figures would be in the answer?
3
If a recipe calls for 0.800 kg of flour, how many ounces of flour does it need?
(1 lb = 16 oz, 1 lb = 0.454 kg)
28.2 oz
Four properties of water are listed.
It has high thermal conductivity.
It reacts with metals to form metal hydroxide and hydrogen gas.
When heated to 100 °C, water evaporates.
It decomposes to form hydrogen and oxygen.
Which are the chemical properties of water?
2 and 4
Refer to the measurements in the table to determine which unidentified metal has the lowest density.
Metal | Volume | Mass |
---|---|---|
A | 12.5 cm3 | 122 g |
B | 15.2 cm3 | 129 g |
C | 13.1 cm3 | 101 g |
D | 18.7 cm3 | 126 g |
Metal D
What is generally true about the compressibility of solids?
It is lower than the compressibility of plasmas and gases.
A student describes the motion of particles in each of the four different states of matter.
State 1: Particles that are charged move freely
State 2: Particles move freely at high speed
State 3: Particles are locked in place
State 4: Particles slide past one another
Which state describes solids?
State 3
Which of the following describes the characteristics of a solid?
Particles are packed closely together in an organized way and maintain their set shape and volume.
Volume is an extensive physical property because it is dependent on the size of the sample.
True
Which of the following is a chemical property?
Toxicity
Which of the following is an example of a chemical change?
Burning paper
When heat energy is removed, two changes are observed:
Change A: Gas changes phases to a liquid.
Change B: Liquid changes phases to a solid.
What are the names for phase changes A and B?
A is condensation and B is freezing.
Rubbing alcohol evaporates from your arm quickly, leaving a cooling effect on your skin. How do the molecules of gas compare to the molecules as a liquid?
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles.
Which of the following is a sign a chemical reaction has occurred?
A solid forms when two liquids are mixed
During an experiment, water was heated in a container covered with a glass lid. Water droplets formed on the inside of the glass lid, and bubbles in the water rose as the water boiled.
Identify if this heating of water to boiling was a physical or chemical change.
Justify your answer.
In this experiment, water is boiled, which is a physical change. Boiling water is a physical change because the water is not being changed at the molecular level. The molecules will still be H2O regardless of the form of the water, making boiling a physical change.
What type of mixture is chicken noodle soup?
A heterogeneous mixture, because the different components are mixed unevenly within the substance
Which of the following correctly describes a compound?
The atoms can only combine in fixed ratios, and they can only be separated by a chemical change.
When you are dissolving sugar in your coffee, the last spoonful of sugar won't dissolve no matter how much you stir. What type of solution have you made?
A saturated solution
Which of the following pairs of substances would best be separated using a centrifuge, and why?
Cream and milk, because of their difference in density
Water is an example of a mixture because it is made up of hydrogen and oxygen atoms bonded together.
False
During an experiment, it is observed that iron powder sinks in water and sulfur powder floats in water. What will most likely be observed when sulfur powder and iron powder are mixed together and then added to water?
Sulfur will float and iron will sink because each will retain its properties.