3. The atmosphere that covers our planet is considered a(n)- a. Element square b. Compound c. Mixture d. Organic compound

The correct answer is c. Mixture.The atmosphere that covers our planet is considered a mixture. A mixture is a combination of two or more substances that are not chemically bonded together. The atmosphere is composed of various gases, such as nitrogen, oxygen, carbon dioxide, and trace amounts of other gases, which are not chemically bonded but are physically mixed together.