Physical And Chemical Science Quiz

Explanation
Scientists have discovered more than 3000 rocks and minerals. This indicates that there is a wide variety of rocks and minerals that have been identified and studied by scientists. The large number suggests that there is a vast amount of diversity in the types of rocks and minerals found on Earth.

Explanation
When fire burns wood, it undergoes a chemical change. This is because the wood reacts with oxygen in the air to produce heat, light, and new substances like carbon dioxide and water vapor. The original composition of the wood is altered, making it a chemical change rather than a physical change. In a physical change, the substance may change its state or appearance, but its chemical composition remains the same. However, in this case, the wood is being transformed into different substances, indicating a chemical change.

Explanation
The sun is composed of plasma. Plasma is a state of matter that is similar to gas, but it consists of highly charged particles. In the sun, the high temperatures and pressures cause the atoms to lose their electrons, resulting in a plasma state. This plasma is made up of positively charged ions and free electrons, creating a highly energetic and electrically conductive environment. As a result, the sun emits light and heat, and it undergoes nuclear fusion reactions to release vast amounts of energy.

Explanation
The diamond is the hardest mineral on the Mohs scale, which measures the hardness of minerals based on their ability to scratch other minerals. A diamond has a hardness of 10, making it the top of the scale. This means that it can scratch any other mineral on the scale and is extremely durable.

Explanation
Flammability refers to the ability of a substance to burn or ignite. It is a characteristic that describes how easily a material can undergo a chemical reaction with oxygen, resulting in combustion. Since flammability involves a chemical reaction, the correct answer is chemical.