Friday STEAM: Solids

Molecules

• When you combine them, you can make millions of different molecules.
• Molecules are groups of atoms.
• Atoms bond together when the outer shell of the electrons is not full.
• They can share electrons, making a covalent bond, or they can just borrow them, and make an ionic bond.

Compounds

• Smaller molecules can work together and build macromolecules. It just goes on from there.
• A compound is a molecule made of atoms from different elements.
• There are millions of different compounds around you.
• New compounds have few or none of the physical or chemical traits of the original elements. They have a new life of their own.

Mass

• Mass is the amount of matter in an object. You might have a small object with a lot of mass such as a statue made of lead. You might have a large object with very little mass such as a balloon filled with helium.
• There is a difference between mass and weight.
• Mass is a measure of the matter in an object while weight is a measure of gravity’s pull on an object.

Volume

• Volume is the amount of space something occupies.
• Words such as big, little, long, or short are used to describe volumes.
• A marble takes up a small volume while a star occupies a large volume.
• Different states of matter will fill volumes in different ways.

Physical State

Physical States

• The physical state and energy in the atoms and molecules determines the state of matter.
• Solids have physical properties of a solid often include "hard" and "brittle."
• Liquids are fluidy, move around a little, and fill up containers.
• Gases are always around you, but the molecules of a gas are much farther apart than the molecules in a liquid. If a gas has an odor, you’ll often be able to smell it before you can see it.

Physical Change

• Molecules can move from one physical state to another (phase change) and not change their atomic structure.
• Although its physical state may change because of different amounts of energy, its atomic structure remains the same.
• Physical changes are related to changes in the immediate environment such as temperature, pressure, and other physical forces.

Phase Change

• Phase changes happen when you reach certain special points.
• Scientists use something called a freezing point or melting point to measure the temperature at which a liquid turns into a solid.
• When you reach your boiling point, the molecules in your system have enough energy to become a gas. When you reach the temperature of the condensation point, you become a liquid.

Crystals

Crystals

• A crystal is a form of solid where the atoms are arranged is a very specific order.
• Crystals are often pure substances and not all substances can form crystals because it is a very delicate process.
• The atoms are arranged in a regular repeating pattern called a crystal lattice.

Mixtures

Mixtures

• If you have different types of molecules dissolved in a liquid, it is called a solution. Honey is a solution of sugar, water, and other molecules.
• Solutions are groups of molecules that are mixed and evenly distributed in a system. Scientists say that solutions are homogenous systems.
• Heterogeneous mixtures have a little more of one thing in one part of the system when compared to another.

Solids

Structure

• In the same way that a large solid holds its shape, the atoms inside of a solid are not allowed to move around too much.
• Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want.
• The molecules in a solid are stuck in a specific structure or arrangement of atoms.