1.
If a solid object is taken from Earth far into space, which of the following measurements of the object will change MOST?
Correct Answer
D. Weight
Explanation
When a solid object is taken from Earth far into space, the measurement that will change the most is its weight. Weight is the force of gravity acting on an object, and since the object is far away from Earth, the force of gravity acting on it will be significantly reduced or even negligible. However, the mass, volume, and density of the object will remain the same because they are intrinsic properties of the object and do not depend on the gravitational force.
2.
Which of the following is an example of a container that is filled with a pure substance rather than a mixture?
Correct Answer
C. A balloon filled with helium
Explanation
A balloon filled with helium is an example of a container that is filled with a pure substance rather than a mixture. Helium is an element and is considered a pure substance because it consists of only one type of atom. In contrast, the other options involve mixtures. Air is a mixture of gases, salt water is a mixture of salt and water, and chocolate milk is a mixture of milk and chocolate syrup. Therefore, the correct answer is a balloon filled with helium.
3.
The table below shows the number of each kind of atom that makes up one molecule of the compounds sucrose and ethanol.
Compound: sucrose (12 atoms of carbon, 11 atoms of oxygen, and 22 atoms of hydrogen) and:
ethanol (2 atoms of carbon, 1 atom of oxygen, and 6 atoms of hydrogen).Which of the following is the SAME for both compounds?
Correct Answer
D. The types of atoms in each molecule
Explanation
The correct answer is "the types of atoms in each molecule." This means that both sucrose and ethanol have the same types of atoms in their respective molecules. The number of atoms and the mass of each molecule may be different for each compound, but the types of atoms remain the same.
4.
A student is given a sample of an unknown liquid to test in the laboratory. The student thinks that the liquid is water. Which of the following physical properties of the sample is MOST helpful to determine if the liquid is water?
Correct Answer
A. Boiling point of the liquid
Explanation
The boiling point of a liquid is a physical property that is unique to each substance. Water has a boiling point of 100 degrees Celsius (212 degrees Fahrenheit) at sea level. By measuring the boiling point of the unknown liquid, the student can determine if it matches the boiling point of water, which would confirm that the liquid is indeed water. The color, volume, and mass of the liquid do not provide specific information about its identity as water.
5.
Which of the following is formed when two elements combine chemically?
Correct Answer
B. A compound
Explanation
When two elements combine chemically, they form a compound. A compound is a substance composed of two or more different elements that are chemically bonded together. This chemical bonding results in the formation of a new substance with different properties than its constituent elements. Compounds have a fixed composition and can be represented by a chemical formula. Examples of compounds include water (H2O), carbon dioxide (CO2), and sodium chloride (NaCl).
6.
Mrs. Collette measured the mass of a closed beaker containing several ice cubes. The mass was 100 g. An hour later, after the ice cubes had melted, Mrs. Collette measured the mass of the beaker again.
What was the mass of the beaker of water the second time?
Correct Answer
B. 100 g
Explanation
The mass of the beaker of water the second time would still be 100 g. This is because when the ice cubes melted, they transformed into water, which did not change the mass of the beaker. Therefore, the mass of the beaker remained the same.
7.
New carpet is being measured for a room that a 5.5 m by 4.6 m. On a measuring tape, what is the smallest unit that is NECESSARY to measure the room accurately for the carpet?
Correct Answer
D. Centimeters
Explanation
To measure the room accurately for the carpet, the smallest unit necessary is centimeters. This is because centimeters provide a more precise measurement than meters or kilometers, and millimeters would be too small and unnecessary for measuring the room accurately.
8.
Sugar is composed of carbon, hydrogen, and oxygen. Sugar is an example of which of the following?
Correct Answer
C. A compound
Explanation
Sugar is composed of carbon, hydrogen, and oxygen, which indicates that it is made up of different elements chemically bonded together. A compound is a substance formed by the chemical combination of two or more elements in a fixed ratio, and sugar fits this definition. Therefore, sugar is considered a compound.
9.
The surface of a heated metal object measures 120 degrees celsius. It is dropped into a bucket filled with water measuring 10 degrees celsius.
Which of the following is most likely to occur?
Correct Answer
D. The water and metal will adjust to the same temperature between 10 and 120 degrees celsius.
Explanation
When the heated metal object is dropped into the bucket of water, heat transfer will occur between the metal and the water. The metal, which is initially at a higher temperature of 120 degrees Celsius, will transfer heat to the water, which is initially at a lower temperature of 10 degrees Celsius. This heat transfer will continue until both the metal and water reach a common temperature. Therefore, the most likely outcome is that the water and metal will adjust to the same temperature between 10 and 120 degrees Celsius.
10.
A pot of water was heated on a stove until the water boiled. Which of the following BEST explains why the water was able to boil?
Correct Answer
A. The cold water absorbed heat from the pot.
Explanation
The correct answer is "The cold water absorbed heat from the pot." When the pot of water is heated on the stove, the heat energy is transferred from the stove to the pot, and then from the pot to the water. The water molecules gain kinetic energy from the heat, causing them to move faster and eventually reach their boiling point. This absorption of heat by the cold water leads to the boiling process.