Grade 5 Science Practice Test: Matter, Ecosystems and Earth's Systems

Matter is made of particles that are too small to see. When sugar dissolves, it separates into these tiny particles, which spread all through the water. The sweet taste is evidence that the sugar is still there; if the water evaporated, the sugar would be left behind.

The fizzing shows that a gas formed. In the sealed bag the gas was trapped, so the total stayed at 180 g; in the open cup the gas escaped into the air and took 4 g of mass with it. Gas is matter and has mass, and no matter was destroyed in either setup.

Only aluminum foil matches all three results: it does not dissolve, a magnet does not attract it, and it conducts electricity. The iron nail also conducts electricity, but a magnet attracts it, so it does not match.

A solid appearing when two clear liquids are mixed means the particles rearranged into a substance that was not there before. Melting only changes the state of water, and the salt-and-pepper and sand-and-water mixtures still contain their original substances.

Earth's gravity pulls objects toward the center of the planet. For people anywhere on Earth, that direction is "down," toward the ground under their feet. Australia only looks like the bottom of the world because of the way maps and globes are usually drawn.

The grass used energy from sunlight to make its food, and some of that energy was stored in its seeds. The energy then passed to the mouse, the snake and finally the hawk. Soil minerals and water are materials the grass needs, but they are not the source of the energy.

The soil lost only 3 grams, but the plant gained about 160 grams, so the soil cannot be the main source. Plants build their bodies mostly from water taken in by the roots and carbon dioxide taken from the air. Sunlight gives the plant energy, but light is not matter.

Decomposers such as fungi and bacteria break down dead leaves and return their matter to the soil, where plants can use it again. Producers make their own food, and predators get their food by eating other animals.

Snakes are predators of mice, so with fewer snakes, fewer mice are eaten and the mouse population grows at first. Owls still eat mice, but the loss of the snakes means fewer mice are eaten overall.

The hydrosphere is all of Earth's water, including the ocean, and the geosphere is Earth's rock and soil. Waves wearing rock down into sand is the hydrosphere changing the geosphere. No living things (the biosphere) are part of this example.

The shadow got shorter during the morning, was shortest at 1:00 p.m. and grew longer again in the afternoon. The higher the Sun is in the sky, the shorter a shadow is, and the Sun appears highest around the middle of the day as Earth turns.

Only about 3% of Earth's water is fresh, and ice caps and glaciers alone hold about 2% of all water, which is about two-thirds of the fresh water. Lakes, rivers and the air together hold only a tiny share, even though they are where people see fresh water most often.