Properties of Matter

Lesson 1: What is the structure of matter? Matter is anything that takes up space and has mass. An object’s mass doesn’t change. Volume is the amount of space something takes up. You can pour water into a different glass and it will have a different shape but the volume does not change.

Lesson 1 All matter is made up of tiny particles called atoms. Each atom has a dense area in the center called the nucleus. The nucleus has 2 kinds of particles inside it. Every atom has at least one proton with a positive charge and most also have a neutron with no charge at all. Electrons travel around the nucleus and are much smaller than protons and neutrons. Electrons have a negative charge.

Lesson 1: When 2 or more atoms join together, they form a molecule. Water is made up of molecules. Each water molecule has one oxygen atom and two hydrogen atoms. Oxygen and hydrogen are both gases at room temperature. When oxygen and hydrogen come together though, they form a liquid (water) at room temperature.

Lesson 1: An element is matter composed of just one kind of atom. Hydrogen gas is made of only hydrogen atoms so it is an element. Water is made of hydrogen and oxygen so it is not an element. Scientists have identified 116 elements. Some of them are familiar to you like neon which is in neon signs. Or gold which is what your mom’s ring is made of.

Lesson 1: Scientists organize the elements with the periodic table. This is a large chart that arranges the elements by their atomic number. An elements atomic number is the number of protons in its nucleus. The chart also shows the element’s name and symbol.

Lesson 1: Some of the boxes on the periodic table have different colors. The colors show the different states of matter (gas, solid, liquid). A solid has its own shape and volume and the particles (atoms) are close together. A liquid has its own volume but takes the shape of the container that it’s in. Its particles are a little farther apart. A gas takes the shape and volume of its container and the particles are far apart and move fast.

Lesson 2: What are physical properties and changes? Water can change from one state to another. It can be a liquid, solid, or a gas. Matter that can change physical state is called physical change. Many physical changes are caused by heating or cooling.

Lesson 2: Ice melts at 32 degrees. It is called the melting point of water. Water always boils at 212 degrees. This is called the boiling point.

Lesson 2: To find density, you divide the mass by the volume. The four cubes in the picture below have the same volume but have different amounts of mass. Therefore, they have different densities.

Lesson 2: Density is a physical property of matter. Density tells how concentrated the matter is. Every kind of matter has it’s own density.

Lesson 2: A mixture is a combination of 2 or more different substances. The substances in the mixture keep their own properties and do not permanently combine. You can separate the substances and get back what you started with.

Lesson 2: If you make a mixture of sugar and water, the sugar will disappear into the water. This becomes a solution. A solution is a mixture in which all part mix evenly.

Lesson 2: You see physical changes every day. Cutting paper is a physical change. Bending a piece of cardboard is a physical change. You can also see physical changes in nature. When a puddle evaporates or your breath condenses on a cold day.

Lesson 3: What are chemical properties and changes? Chemical changes are different from physical changes. A chemical change forms a new substance.

Lesson 3: Burning has a special name in science: combustibility. The combustibility of a substance is a measure of how easily it burns when combined with oxygen. Corrosion is another chemical change that happens to metals. An example of corrosion is when iron forms with oxygen in the air to form rust.

Lesson 3: The ability of a substance to react, or go through a chemical change, is called reactivity. A change is color will also tell you that a chemical change has occurred. When you watch fireworks, you are watching chemical changes. In a fireworks display: If you see blue, you are watching copper burn. Burning aluminum produces a white color. Strontium burns red. Barium burns green.

Lesson 3: Chemical changes do not make new matter. They change the matter of the substances you had before but the mass of the substances you have before the chemical change will equal the mass of the substances after the chemical change. This is called the Law of Conservation of Matter.