NC Check in :Chemistry

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include boiling water and melting wax.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include rusting iron and baking a cake.

Front

List the elements in order from least reactive to most reactive: Sr, K, Cl, P.

Back

Cl, P, Sr, K

Front

What are isotopes?

Back

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons.

Front

Which element is a poor conductor of heat: Ne, Mg, Ca, Na?

Back

Ne (Neon) is a poor conductor of heat.

Front

What does a balanced chemical equation demonstrate about the Law of Conservation of Mass?

Back

A balanced chemical equation shows that during a chemical reaction, the total amount of matter stays the same.

Front

What is the definition of reactivity in chemistry?

Back

Reactivity refers to the tendency of a substance to undergo a chemical reaction, either by itself or with other materials.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is a substance formed when two or more elements are chemically bonded together.

Front

What is the periodic table?

Back

The periodic table is a tabular arrangement of chemical elements, organized by their atomic number, electron configuration, and recurring chemical properties.

Front

What is the significance of the atomic number?

Back

The atomic number of an element is the number of protons in its nucleus and determines the element's identity.