To put things into groups based on shared characteristics.

To share ideas, results, or information with others.

To look at two or more things and find how they are alike or different.

To state what you learned, based on evidence.

Information collected during an investigation, often in the form of numbers or observations.

A process engineers use: plan a solution, build and test it, then use what you learn to improve it.

A person who uses science and math to design and build solutions to problems.

Data or observations that support or reject an idea.

To make a reasonable guess about something based on evidence, not just observation alone.

To explain what a set of data or evidence means.

To study a question closely, often by testing it.

To explain the reasons behind a claim, using evidence to back it up.

To find the size, length, mass, or amount of something using a tool.

To use your senses — sight, hearing, touch, smell — to gather information.

To arrange information or objects in a clear, useful order.

A testable statement about what you think will happen, made before an investigation, often in an if-then form.

A request for information that can guide an investigation.

To write down or otherwise capture data during an investigation.

To find and explain a connection between two or more ideas.

A way of studying the natural world using observation, evidence, and testing.

Describes a substance with a pH below 7. Lemon juice and vinegar are common examples.

A measure of how much a substance behaves like an acid — the lower the pH, the higher this is.

A measure of how much a substance behaves like a base — the higher the pH, the higher this is.

The smallest particles that make up all matter, made of protons, neutrons, and electrons.

Describes a substance with a pH above 7. Baking soda and soap are common examples.

How matter can change form: a physical change alters shape or state without making a new substance, while a chemical change creates a new substance entirely.

A written way to show what happens in a chemical reaction, using symbols for the starting and ending substances.

Substances made of two or more different elements chemically bonded together.

The scientific rule that mass is neither created nor destroyed during a chemical reaction — it just gets rearranged.

The basic substances that make up all matter — each one cannot be broken down into anything simpler by chemical means.

Another name for the columns of the periodic table — used because elements in the same one behave in similar ways, like members of a family.

The columns of the periodic table. Elements in the same one share similar chemical properties.

A substance that changes color to show whether something is acidic or basic.

A strip of paper that turns red in acids and blue in bases, used to quickly test a substance's pH.

Elements that are typically shiny, bendable, and good at conducting heat and electricity.

Two or more substances combined physically, without any new substance forming — each part keeps its own properties.

Two or more atoms bonded together.

Describes a substance with a pH of exactly 7 — neither acidic nor basic. Pure water is a common example.

A group of elements on the periodic table that rarely react with other elements.

Elements that are typically dull, brittle, and poor at conducting heat and electricity.

A chart that organizes all known elements by their properties and atomic structure.

The rows of the periodic table.

A number, usually from 0 to 14, that measures how acidic or basic a substance is.

The full range of values, from 0 (most acidic) to 14 (most basic), used to measure acidity.

A change of state — like solid to liquid, or liquid to gas — without changing what the substance is made of.

A chemical indicator that stays clear in acids but turns pink in bases.

The characteristics that describe matter, such as color, hardness, or density.