Element and mixture

What is the definition of an element?

• A substance that can be broken down into simpler substances by physical means.

• A pure substance that cannot be broken down into two or more simpler substances by chemical processes.

• A mixture of two or more different types of atoms.

• A substance that changes its properties when heated.

Which of the following is the correct chemical symbol for Carbon?

• Ca

• C

• Co

• Cr

Which of the following is NOT a characteristic property of most metals?

• They are good electrical conductors.

• They are malleable and ductile.

• They have a dull, non-lustrous appearance.

• They are solid at room temperature (with some exceptions).

What is the fundamental unit of an element?

• A molecule

• A compound

• An atom

• A mixture

What defines a chemical compound?

• Two or more identical atoms combined.

• Two or more different atoms chemically combined.

• A substance that cannot be broken down further.

• A substance formed by mixing elements without chemical bonding.

What type of compound is formed when a metal element combines with a non-metal element?

• Covalent compound

• Molecular compound

• Ionic compound

• Elemental compound

How do the properties of a compound relate to the properties of the elements that form it?

• Compounds always retain the exact properties of their constituent elements.

• Compounds have entirely different properties from the elements that form them.

• Compounds only retain the properties of the most abundant element.

• Compounds have properties that are a simple average of their constituent elements.

Which characteristic describes a chemical mixture?

• Components are chemically bonded together.

• Components retain their individual chemical properties.

• Components are always present in a fixed ratio.

• A significant energy change occurs during its formation.