How would the universe look without gravity? It would have no planets and no stars. Thats how it looked when it was young. When the universe was young, there was only gas and dust. From this gas and dust, everything we now see was made. How were stars and planets created from just gas and dust? The answer is gravity. The same gravity that holds you down on Earth. The same force that causes your pencil to roll off your desk. The same force that causes it to fall to the floor. The invisible force of gravity caused dust and gas particles to be pulled together. This force is what formed all the objects in our solar system. This force formed the smallest moons. It also formed our Sun. This force caused more than just our solar system to form. It caused all the other solar systems to form. It caused the formation of all the galaxies of the universe.

What are some things that gravity does?

Have you ever seen an egg? Some animals do not have live births. Instead, they lay eggs. The eggs contain the embryo. The embryo matures in the egg. With time, it will hatch. Some animals hatch and do not need care from their parents. They are ready to live on their own. Other animals will still need the care of their parents. Sea turtles break out of their shells. They immediately walk to the ocean. They do this with no help from an adult. Birds stay in the nest for many weeks. They are cared for by their parents. They leave the nest when they are strong enough to fly. Some animals give birth to live offspring. Animals like horses, cows, and whales give live birth. Their offspring are born looking like mini adults.

Give an example of an animal that does not need the care of its parents after birth.

Physical properties include the state of matter. We know these states as solid, liquid, or gas. Properties can also include color and odor. For example, oxygen is a gas. It is a major part of the air we breathe. It is colorless and odorless. Chlorine is also a gas. In contrast to oxygen, chlorine is greenish in color. It has a strong, sharp odor. Have you ever smelled cleaning products used around your home? If so, you have probably smelled chlorine. Another place you might smell chlorine is at a public swimming pool. The chlorine is used to kill bacteria that may grow in the water. Other physical properties include hardness, freezing, and boiling points. Some substances have the ability to dissolve in other substances. Some substances cannot be dissolved. For example, salt easily dissolves in water. Oil does not dissolve in water.
Which gas is found in cleaning products?