During a chemical reaction, a fixed amount of iron combines completely with a fixed amount of oxygen to form iron oxide. Which statement best describes the mass of the iron oxide that is produced? A. The mass is equal to the mass of the iron plus the mass of the oxygen.
B. The mass is greater than the combined mass of both the iron and the oxygen.
C. The mass is equal to the mass of the iron minus the mass of the oxygen before reacting.
D. The mass is less than the mass of the iron but greater than the mass of the oxygen before reacting.

metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). the change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. i hoped i !

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: