MIXTURES

Mixtures are mad up of two or more pure substances which can be separated by physical changes.

There are two types of mixtures:

We can separate the pure substances in different ways:

FILTRATION

EVAPORATION

MAGNETIC SEPARATION

CHANGES IN MATTER

There are two different types of changes:

• PHYSICAL CHANGE is a change in the size or the state of matter. Physical change can be caused by MOTION, PRESSURE or TEMPERATURE. In Physical change the molecules of matter don't change.

• CHEMICAL CHANGE happens when the molecules of matter change.Chemical changes usually can not be reversed.

Click here: Scholastic Study Jams: Physical and Chemical Changes of Matter

ATOMS and MOLECULES

WHAT ARE ATOMS?

• ATOM is the smallest part of the matter. 
• Atoms are made up of: PROTONS, NEUTRONS and ELECTRONS.
• Protons and neutrons are in the NUCLEUS and electrons are around the nucleus distributed in SHELLS.
• Atoms always have the same number of protons and electrons.
• MOLECULE is made up of atoms.

MAKING MOLECULES WITH ATOMS

• ELEMENTS in the same group have similar chemical and physical properties.
• VALENCE NUMBER is the number of electrons in an atom's outer shell.

MOLECULES IN MOTION

• TEMPERATURE is the measure of molecular movement.

The Three States of Matter

WATER and STATES OF MATTER

Water is life itself, but we are using too much of it. We use it for drinking, washing, transport, electricity, farming and recreation. Only 3% of water on the planet is fresh and just a third of that is accessible to humans. There's been a 35% decline in freshwater species since 1970. we need to harness rivers, lakes and aquifers in ways that won't cause long-term harm. Freshwater ecosystems are worth trillions of dollars each year. They provide food and livehoods for millions. So we should make choices that ensure people and nature have enough water.

STATES OF WATER

CHEMISTRY AND MATTER

What is CHEMISTRY? Chemistry is the study of MATTER and the changes that take place with that matter. 

Everything on Earth, everything in our solar system, everything in our galaxy, and everything in the universe is made up of matter. Matter is the name that scientists have given to everything that you can touch, or see, or feel, or smell. 

Matter is anything made of atoms and molecules. Matter is anything that has mass and takes up space.