Atoms and elements
What is the center of an atom called?
Nucleus
What is a mixture?
A combination of two or more substances that are not chemically bonded.
What state of matter has particles that are tightly packed and only vibrate in place?
Solid
What color does blue litmus paper turn in an acid?
Red
What is the simplest form of a chemical substance that cannot be broken down?
An element
Name the negatively charged particles that orbit the nucleus of an atom
Electrons
What is a solution?
A mixture where one substance (the solute) is completely dissolved in another (the solvent).
What happens to particles in a liquid when it is heated?
They move faster and spread out, potentially turning into a gas.
Name a common household base
Baking soda
What is the chemical symbol for water?
H2O
What do you call a substance made up of only one type of atom?
An element
What is the difference between a solution and a suspension?
In a solution, the solute is completely dissolved and the mixture is uniform, while in a suspension, the particles are dispersed but not dissolved and can settle out over time.
Define diffusion
Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
What is the pH range of acids?
Less than 7
Explain what a chemical reaction is
A chemical reaction is a process where substances (reactants) change into new substances (products) with different properties.
Describe the difference between an atom and a molecule
An atom is the smallest unit of an element, while a molecule is made up of two or more atoms bonded together.
What is a colloid?
A mixture where tiny particles are evenly distributed throughout another substance, and the particles do not settle out.
Describe the particle arrangement in a gas.
Particles in a gas are far apart and move freely in all directions.
Describe one property of a base
Bases have a bitter taste and feel slippery
What is the main difference between a compound and a mixture?
Compounds are chemically bonded, while mixtures are physically combined without chemical bonds.
Give an example of a molecule and explain its composition (what and how many atoms it is made of).
Water (H₂O) is made up of two hydrogen atoms and one oxygen atom
Explain what is meant by an "insoluble" substance and give an example.
An insoluble substance does not dissolve in a solvent. For example, sand is insoluble in water.
What is the main difference between the particles in a solid and a liquid?
Particles in a solid are in a fixed, orderly arrangement, while particles in a liquid are close together but can move past each other.
Give an example of a strong laboratory acid
Hydrochloric acid
Write the word equation for the reaction between hydrochloric acid and sodium hydroxide.
Hydrochloric acid + Sodium hydroxide → Sodium chloride + Water