1.
Endothermic
Correct Answer
A. Matter absorbs heat
Explanation
Endothermic matter refers to substances or systems that absorb heat from their surroundings. This means that when endothermic matter undergoes a reaction or a process, it absorbs heat energy from its surroundings, resulting in a decrease in the temperature of the surroundings. This is in contrast to exothermic matter, which releases heat energy into its surroundings. Therefore, the correct answer is that endothermic matter absorbs heat.
2.
Exothermic
Correct Answer
B. Matter gives off heat
Explanation
Exothermic reactions refer to chemical reactions that release heat energy to the surroundings. In these reactions, matter undergoes a transformation and gives off heat as a byproduct. This can be observed in various processes like combustion, where fuel reacts with oxygen to produce heat and light. Therefore, the correct answer is "matter gives off heat."
3.
During the phase change, sublimation, matter goes from _________________ to _________________.
Correct Answer
C. Solid; gas
Explanation
During the phase change of sublimation, matter goes directly from a solid state to a gas state. This means that the particles in the solid substance gain enough energy to break their bonds and transition into a gaseous state without passing through the liquid phase. This process is commonly observed in substances like dry ice (solid carbon dioxide) which directly converts into carbon dioxide gas without melting into a liquid.
4.
Splitting of the nucleus of an atom is a __________________ change called ________________.
Correct Answer
B. Nuclear; fission
Explanation
The splitting of the nucleus of an atom is a nuclear change because it involves changes in the nucleus of the atom. This process is specifically called fission, which refers to the splitting of a heavy nucleus into two or more lighter nuclei.
5.
Mark the changes that are chemical changes (there is more than one answer)
Correct Answer(s)
A. Burning paper
C. Fireworks
E. Making cottage cheese
G. Acid making a hole in a shirt
Explanation
Burning paper is a chemical change because it involves the combustion of the paper, resulting in the release of heat, light, and new substances (such as ash and smoke). Fireworks also undergo a chemical change as they explode, producing new substances and releasing energy in the form of light and sound. Making cottage cheese involves a chemical change as the milk proteins coagulate and form curds through a process called acidification. Finally, acid making a hole in a shirt is a chemical change because the acid reacts with the fabric, breaking down its chemical structure and causing a hole to form.
6.
The combining of neutrons and protons to form heavier elements is
Correct Answer
B. Nuclear fussion
Explanation
Nuclear fusion is the correct answer because it is the process in which two or more atomic nuclei come together to form a single, more massive nucleus. This process releases a large amount of energy and is the main source of energy in stars, including our Sun. In nuclear fusion, the nuclei of lighter elements, such as hydrogen isotopes, combine to form heavier elements, such as helium. This process is different from nuclear fission, which involves the splitting of heavy atomic nuclei into smaller ones.
7.
Choose the phase changes that are endothermic. (there is more than one answer)
Correct Answer(s)
A. Melting
C. Sublimation
D. Vaporization
Explanation
The phase changes that are endothermic involve the absorption of heat from the surroundings. Melting is the phase change from solid to liquid, where heat is needed to break the bonds between particles. Sublimation is the phase change from solid to gas, where heat is required to break the bonds and turn the solid directly into a gas. Vaporization is the phase change from liquid to gas, where heat is needed to break the intermolecular forces and convert the liquid into a gas. Therefore, melting, sublimation, and vaporization are all endothermic phase changes.
8.
Melting is ___________________ and the amount of particle motion _________________ as heat is added to the matter that is melting.
Correct Answer
C. Endothermic; increases
Explanation
When a substance melts, it absorbs heat from its surroundings, which is why melting is considered endothermic. As heat is added to the matter, the particles within the substance gain energy and begin to move more rapidly, causing an increase in particle motion. Therefore, the correct answer is endothermic; increases.
9.
Solids have a__________________ shape and _______________ volume.
Correct Answer
A. Definite; definite
Explanation
Solids have a definite shape because their particles are closely packed and arranged in a fixed pattern. This allows them to maintain a specific shape and not flow or deform easily. Solids also have a definite volume because their particles are tightly packed together, resulting in a fixed amount of space occupied by the solid.
10.
A substance that is made up of only one kind of atom is
Correct Answer
C. Element
Explanation
An element is a substance that is made up of only one kind of atom. Each element has a unique atomic number and is represented by a specific symbol on the periodic table. Examples of elements include hydrogen, oxygen, and carbon. Elements cannot be broken down into simpler substances by chemical means, making them the building blocks of all matter.
11.
Choose the answers that are examples of chemical properties
Correct Answer(s)
C. Reactivity
E. Flammability
Explanation
The correct answers, reactivity and flammability, are examples of chemical properties. Reactivity refers to the ability of a substance to undergo a chemical reaction and form new substances. Flammability, on the other hand, is the property of a substance to ignite and burn when exposed to a flame or heat. These properties are specific to the chemical composition of a substance and can be used to identify and classify different materials based on their behavior in certain conditions.
12.
All particles of matter are in constant motion
Correct Answer
C. Kinetic particle theory
Explanation
The correct answer is kinetic particle theory because it states that all particles of matter are in constant motion. This theory explains that matter is made up of tiny particles that are constantly moving and vibrating. It helps us understand various properties of matter such as temperature, pressure, and states of matter. The kinetic particle theory is widely accepted and supported by experimental evidence.
13.
A suspension is
Correct Answer
B. Substances will settle into layers over time.
Explanation
The correct answer is "Substances will settle into layers over time." This is because a suspension is a heterogeneous mixture in which solid particles are dispersed in a liquid or gas. These solid particles are larger and heavier than the particles in a solution, so they eventually settle at the bottom over time, forming distinct layers. This settling process is known as sedimentation. Therefore, the statement "Substances will settle into layers over time" accurately describes the behavior of a suspension.
14.
Milk is an example of a ________________.
Correct Answer
C. Colloid
Explanation
Milk is an example of a colloid because it consists of small particles of fat and protein dispersed throughout a liquid, which is water in this case. These particles are not dissolved, but rather suspended in the liquid, giving milk its characteristic cloudy appearance. Colloids are a type of mixture where the particles are larger than those found in a solution but smaller than those found in a suspension.
15.
Matter cannot be created or destroyed, only changed from one form to another form
Correct Answer
C. Law of conservation of matter
Explanation
The given statement "Matter cannot be created or destroyed, only changed from one form to another form" aligns with the law of conservation of matter. This law states that the total amount of matter in a closed system remains constant over time, regardless of any physical or chemical changes that may occur. It implies that matter can neither be created nor destroyed, but it can be transformed into different forms through processes like chemical reactions or phase changes. This principle is fundamental in understanding the behavior and interactions of matter in various scientific fields.
16.
The following are examples of homogenous mixtures
Correct Answer(s)
C. Mountain dew
D. Air
Explanation
Homogeneous mixtures are uniform throughout, meaning that their composition is the same in all parts. Mountain Dew and air can both be considered homogenous mixtures because they have a consistent composition throughout. Mountain Dew is a drink that is made up of various ingredients, such as water, sugar, and flavorings, which are evenly distributed. Similarly, air is a mixture of gases, including nitrogen, oxygen, and carbon dioxide, which are also evenly distributed. Therefore, both mountain dew and air can be classified as examples of homogeneous mixtures.
17.
Condensation is matter that changes from a _______________ to a ____________________ and it is ____________________.
Correct Answer
C. Gas;liquid;exothermic
Explanation
Condensation is the process in which a gas changes into a liquid. This change is exothermic, meaning it releases heat energy. When a gas cools down, its molecules lose energy and slow down, causing them to come closer together and form bonds, resulting in the formation of a liquid. The release of heat energy during this process is what makes it exothermic. Therefore, the correct answer is "gas;liquid;exothermic."
18.
When driving in fog it is best to have your lights on bright, because fog reflects light.
Correct Answer
B. False
Explanation
Having your lights on bright when driving in fog is not recommended because fog reflects light, which can create a glare and reduce visibility even further. It is advisable to use low beam headlights or fog lights instead, as they are designed to cut through fog and provide better illumination without causing excessive glare.
19.
In a sugar water solution, sugar is the solvent.
Correct Answer
B. False
Explanation
In a sugar water solution, sugar is not the solvent, but rather the solute. The solvent is the substance that dissolves the solute, in this case, water. When sugar is added to water, it dissolves and becomes evenly distributed throughout the water, making water the solvent in this solution.
20.
Gases have more particle motion than liquids.
Correct Answer
A. True
Explanation
Gases have more particle motion than liquids because the particles in a gas are not held together tightly and are free to move around in all directions. In contrast, the particles in a liquid are closer together and have less freedom to move. This increased particle motion in gases leads to their ability to fill the entire volume of a container and their tendency to expand when heated.