Chapter 2: Second Half : Matter, Matter And Energy, Properties Of Matter

The study of matter and its changes refers to the field of chemistry. Chemistry is a branch of science that explores the properties, composition, structure, and reactions of substances. It focuses on understanding the behavior of matter and how it interacts with energy. By studying chemistry, scientists can uncover the fundamental principles that govern the physical and chemical properties of all substances, leading to advancements in various fields such as medicine, materials science, and environmental science.

When water changes state from solid to liquid, it is melting. In this process, energy needs to be added to the water molecules in order to separate them and break the bonds holding them together. This added energy allows the water molecules to move more freely and transition from a solid state to a liquid state.

To determine the mass and volume of a fluid in a glass, a graduated cylinder is needed to measure the volume of the fluid accurately. A balance is required to measure the mass of the fluid. By using a graduated cylinder to measure the volume and a balance to measure the mass, one can calculate the density of the fluid.

Volume is the correct answer because it refers to the measurement of how much air is moved through an air-conditioning unit. Volume is a measure of the amount of space occupied by a substance, in this case, the amount of air being moved. This measurement is important in air-conditioning units as it determines the amount of air being circulated and the effectiveness of the cooling or heating process. Density, length, and temperature are not directly related to the measurement of how much air is moved through the unit.

The process described in the "previous question" is called condensation. Condensation refers to the transformation of a gas or vapor into a liquid state. It occurs when the temperature of the gas or vapor decreases, causing the molecules to come closer together and form liquid droplets. This process is commonly observed when warm, moist air comes into contact with a cold surface, such as when water vapor in the air condenses on a cold windowpane.

As water changes state from liquid to gas, the process is known as evaporation. During evaporation, the fastest moving molecules break away from the surface of liquid water and form water vapor. This occurs because the fastest moving molecules have enough energy to overcome the attractive forces between water molecules and escape into the gas phase.

The process described in the previous question is called vaporization/evaporation. This term refers to the change of state from liquid to gas, as well as the reverse process of condensation. During vaporization/evaporation, energy is transferred from the surroundings to the water molecules, causing them to gain enough energy to break the intermolecular forces and transition from a liquid to a gaseous state. Conversely, during condensation, energy is transferred from the gas molecules to the surroundings, causing them to lose energy and transition from a gaseous to a liquid state.

Molasses has the greatest viscosity among the given substances. Viscosity is a measure of a fluid's resistance to flow, and molasses is a thick and sticky liquid. It has a higher viscosity compared to vinegar, cooking oil, and water, which are more fluid and less resistant to flow.

As water vapor returns to the liquid water state, water molecules slow down. This is because as water vapor cools and condenses, the molecules lose energy and their movement becomes slower. The transition from a gas to a liquid involves a decrease in molecular motion, causing the water molecules to slow down.

The hypothesis that the water magically disappeared into another dimension is not testable because it involves a supernatural explanation that cannot be proven or disproven through scientific methods.

During the process of vaporization/evaporation, energy is absorbed. This is because when a substance undergoes vaporization, the molecules gain energy from the surroundings, usually in the form of heat. This added energy allows the molecules to overcome the intermolecular forces holding them together, causing them to transition from a liquid to a gaseous state. Therefore, the process of vaporization requires the absorption of energy.

During the process of condensation, energy is released. When a gas or vapor cools down and turns into a liquid, it releases heat energy. This is because the particles in the gas or vapor lose energy and slow down, causing them to come closer together and form a liquid. The released energy is usually in the form of heat, which is why condensation often feels warm.

Centimeters could be used to measure the length of a mineral sample because centimeters are a unit of length. Degrees Celsius measures temperature, milliliters measures volume, and kilograms measures weight. Therefore, the correct unit to measure the length of a mineral sample is centimeters.

Water is an example of matter because it has mass and takes up space. Matter is anything that has mass and occupies space, and water fits this definition. It has a specific volume and can be measured, indicating that it occupies space. Additionally, water has mass, which can be determined by weighing it. Therefore, water is a clear example of matter.

The correct answer is 25.3 because the question asks for the volume of a container needed to hold 25.3 kg of water. The volume of a container needed to hold a certain amount of water is directly proportional to the weight of the water. Therefore, if the weight of the water is 25.3 kg, then the volume of the container needed would also be 25.3.

To determine the number of grams of tin required to fill a 5.52 L container, we need to use the density of tin. The density of tin is given as 7.265 g/cm3. Since 1 cm3 is equal to 1 mL, we can convert the volume of the container from L to cm3 by multiplying it by 1000. Therefore, the volume of the container is 5520 cm3. To calculate the mass of tin, we multiply the volume by the density: 5520 cm3 * 7.265 g/cm3 = 40099.8 g. Rounding this to the nearest tenth gives us 40.10 g, which is the correct answer.

The density of a substance is calculated by dividing the mass of the substance by its volume. In this case, the mass is given as 31 g and the volume is given as 68 cm3. By dividing 31 g by 68 cm3, we get a value of approximately 0.455 g/cm3. Rounding this to the nearest hundredth gives us 0.46 g/cm3, which matches the given answer of .46 g/cm3.

a. It reacts with hydrogen to form a gas - This is a chemical property of sulfur because it involves a chemical reaction between sulfur and hydrogen to produce a new substance, gas.
b. Its density is 2.97 g/cm3 - This is a physical property of sulfur because it describes a characteristic of sulfur that can be measured without changing its chemical composition.
c. Its melting point is 112 degrees C - This is a physical property of sulfur because it describes the temperature at which sulfur changes from a solid to a liquid, without any chemical reaction taking place.
d. It combines with oxygen - This is a chemical property of sulfur because it involves a chemical reaction between sulfur and oxygen to form a new substance.
e. It is a yellow solid - This is a physical property of sulfur because it describes its appearance and state at room temperature, without any chemical reaction taking place.

The given answer is correct.

a. It is a white, waxy solid - This is a physical property because it describes the appearance and state of phosphorus.
b. It burns in air - This is a chemical property because it describes the ability of phosphorus to undergo a chemical reaction.
c. Its melting point is 44.1 degrees C - This is a physical property because it describes the temperature at which phosphorus changes from a solid to a liquid.
d. It has a density of 1.82 g/cm3 - This is a physical property because it describes the mass per unit volume of phosphorus.
e. Its boiling point is 280.3 degrees C - This is a physical property because it describes the temperature at which phosphorus changes from a liquid to a gas.

a. Bending a metal rod is a physical change because it does not alter the chemical composition of the metal.
b. Cooking involves chemical changes as the heat causes chemical reactions in the food.
c. Burning propane is a chemical change as it undergoes combustion to produce carbon dioxide and water vapor.
d. Burning wood is also a chemical change as it undergoes combustion to produce carbon dioxide, water vapor, and ash.
e. Painting wood is a physical change as it does not alter the chemical composition of the wood, only its appearance.
f. Breaking glass is a physical change as it does not alter the chemical composition of the glass, only its physical shape.

Viscosity is the measure of a fluid's resistance to flow. It describes the internal friction of a fluid as it flows, and determines how easily the fluid can be deformed or moved. A fluid with high viscosity, such as honey, has a high resistance to flow and flows slowly, while a fluid with low viscosity, such as water, has a low resistance to flow and flows more easily. Therefore, viscosity is the correct answer to the question about the resistance of a fluid to flow.

Energy is the ability to change or move matter. It can be transformed from one form to another, such as potential energy to kinetic energy. Energy is required to perform work or cause a change in an object's state. It exists in various forms, including thermal, electrical, chemical, and mechanical energy. The ability of energy to change or move matter is evident in everyday life, from the movement of vehicles to the heating of water.

Reactivity refers to the ability of a substance to chemically combine with another substance. It describes how likely a substance is to undergo a chemical reaction when it comes into contact with another substance. A highly reactive substance readily reacts and forms new compounds, while a less reactive substance may require specific conditions or stimuli to undergo a chemical reaction. Therefore, reactivity is a measure of the chemical activity of a substance and its propensity to form new chemical bonds.