Chemical And Physical Properties

Explanation
Water is considered the universal solvent because it has the ability to dissolve a wide range of substances. This is due to its unique molecular structure, which allows it to form hydrogen bonds with other molecules. These hydrogen bonds break apart the solute particles and surround them, dispersing them evenly throughout the solvent. Water's polarity also enables it to dissolve both polar and nonpolar substances, making it an effective solvent for many different compounds. Additionally, water's abundance and accessibility in nature make it the most widely used solvent in various biological, chemical, and industrial processes.

Explanation
One unique property of water is that its solid state, ice, is less dense than its liquid state. This means that ice floats in water, which is not commonly observed with other materials. This property is due to the hydrogen bonding between water molecules, which causes them to arrange in a lattice structure when frozen, resulting in increased space between the molecules and lower density.

Explanation
The list of physical properties of a substance that can be observed or measured without changing its identity includes color, shape, texture, odor, melting point, boiling point, density, and solubility. These properties can be determined through visual observation or by conducting experiments that do not alter the chemical composition of the substance.

Explanation
Combustibility refers to the ability of a substance to burn. It is a chemical property that indicates the likelihood of a material to ignite and sustain a fire or combustion process. Substances with high combustibility are easily ignited and burn readily, while those with low combustibility require more heat or oxygen to ignite. Acidity, reactivity, and basicity are other chemical properties that are unrelated to the ability to burn.

Explanation
Temperature measures the average kinetic energy of the atoms and molecules in matter. It is a measure of how fast the particles are moving and how much energy they possess. The higher the temperature, the greater the average kinetic energy of the particles. Temperature is typically measured in units such as degrees Celsius or Fahrenheit.

Explanation
Water freezes at 0 degrees Celsius because this is the temperature at which its molecules slow down and form a solid lattice structure. At temperatures below 0 degrees Celsius, water molecules lose energy and arrange themselves into a crystal lattice, resulting in the formation of ice.

Explanation
In this experiment, the independent variable is the lights. The independent variable is the factor that is intentionally manipulated or changed by the researcher. In this case, the researcher is placing the plants under different colored lights. By doing so, they are testing how different colored lights might affect the growth or development of the plants. The other variables, such as the soil, the plants, and the water, are kept constant in order to isolate the effect of the lights on the plants.

Explanation
The dependent variable in this question is the height the plants grow. The dependent variable is the factor that is being measured or observed in an experiment and is expected to change in response to the independent variable. In this case, the height of the plants is being measured, and it is expected to vary based on the other variables such as the soil, water, and lights.

Explanation
In an experiment, the materials that are kept the same, such as the soil, water, and plants, are called constants. These are factors that are intentionally kept unchanged throughout the experiment in order to isolate and analyze the effect of the independent variable on the dependent variable. By keeping these materials constant, any changes observed in the dependent variable can be attributed solely to the independent variable being tested.