HELP QUICK!! which elements are most common in a molecule of lactose?
1. copper and nitrogen
2. carbon and hydrogen
3. iron and phosphorus

B.) Carbon and Hydrogen

Explanation:

Lactose is a carbohydrate, and carbohydrates are primarily made of carbon and hydrogen chains.

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.