Experimental Variables and Scientific Research Quiz

Experiment and Research

• An experiment is a set of controlled observations that test a hypothesis.
• A variable is a quantity or condition that has more than one value.
• Independent variable is the plan you plan to change during the experiment.
• Dependent variable is the variable that changes in response to a change in the independent variable.
• Scientific law is a relationship in nature that is supported by many experiments.
• Pure research is conducted to gain knowledge for the sake of knowledge itself.
• Applied research is undertaken to solve a specific problem.

Experiment Components

• A control is a standard for comparison.
• A constant is a variable that is not allowed to change during the experiment.
• A conclusion is a judgment based on the information obtained.
• A theory is an explanation of a natural phenomenon based on many observations and investigations over time.

Properties and States of Matter

• Matter can be found in the solid, liquid, gaseous, or plasma state.
• A solid is a form of matter that has its own definite shape and volume.
• A liquid is a form of matter that flows, has constant volume, and takes the shape of the container.
• A gas is a form of matter that not only takes the shape of the container but also fills the entire volume of the container.
• Plasma is another state of matter that is present in places with very high temperatures.
• Vapor is a gaseous state of a substance that is solid or liquid in room temperature.

Physical Properties

• A physical property is a characteristic of matter that can be observed or measured without changing the composition of the sample.
• Physical properties usually describe pure substances.
• Physical properties are of two types: Extensive and intensive properties.
• Extensive properties are dependent on the amount present in the substance like mass.
• Intensive properties are independent on the amount present in the substance like density.

Chemical Properties

• A chemical property is the ability or inability of a substance to combine with or change into one or more other substances.
• A physical change is a change that changes the substance without changing its composition.
• A chemical change is a process that involves one or more substances changing into new ones.
• Evidence of chemical reactions includes changes in color, taste, elimination of gas, or a precipitate.

Law of Conservation of Mass

• The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction.
• Mass of reactants = mass of products