What is an element in chemistry?

• A pure substance that cannot be broken down into simpler substances by chemical means

• A substance formed when two or more elements are chemically bonded together

• A combination of two or more substances that are not chemically bonded

• A homogeneous mixture with uniform composition

Which of the following is an example of a compound?

• Oxygen

• Gold

• Water

• Salad

Tags

NGSS.MS-PS1-1

How can the components of a mixture be separated?

• By chemical reactions

• By physical means

• By breaking chemical bonds

• By using the periodic table

What is a characteristic of a homogeneous mixture?

• It has visibly different parts or phases

• It has a uniform composition throughout

• It is made up of only one type of atom

• It can be broken down into simpler substances

Which of the following statements is true about compounds?

• They retain the individual properties of their components

• They can be separated by physical means

• They have unique properties different from the elements that form them

• They are listed in the periodic table