So far we've found out a lot about matter. Matter is anything that has mass and takes up space. All matter can be broken down into tiny particles called elements. Understanding the properties of these elements can help us best use materials. Now we're going to look at three properties that all matter has: mass, volume, and density.

Mass of an object is a measure of how much matter it has. We can understand mass by thinking about weight. In science mass is measured in grams (g) or kilograms (kg) (1kg = 1000g). Other units for mass (weight) are pounds and ounces.