Select the gas.
oxygen hammer ruler clothespin
Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms.
When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own.
Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid.
When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle.
Some liquids do not pour as easily as others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk.
When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space.
Many gases are invisible. Air is a gas.
Oxygen is a gas. A gas expands to fill a space. Oxygen can be stored in metal tanks. If oxygen leaks out of the tank, the oxygen will expand into the space around the tank.
A clothespin is a solid. A solid has a size and shape of its own. You can open or close a clothespin. But it will still have a size and shape of its own.
A ruler is a solid. A solid has a size and shape of its own. If you put a ruler in a box, the ruler will keep its shape.
A hammer is a solid. A solid has a size and shape of its own. A hammer is made of iron and wood. Both iron and wood are solids.