The first one because just think about how light oxygen or air is
Answer:
The two hydrogen atoms and one oxygen atom within water molecules (H2O) form polar covalent bonds. ... As a result of water's polarity, each water molecule attracts other water molecules because of the opposite charges between them, forming hydrogen bonds
Answer;
Insulin and the growth hormone
The hormones that are involved in building and maintaining healthy bone tissues are Insulin and growth hormone
Explanation;
Insulin has some anabolic properties for bone. It is uncertain whether insulin stimulates bone directly or indirectly by increasing muscle work and thus skeletal loading.
Growth hormone is a peptide hormone secreted from the pituitary gland under the control of hypothalamus. It directly and through IGF-I stimulates osteoblast proliferation and activity, promoting bone formation. Additionally it stimulates osteoclast differentiation and activity,promoting bone resorption.
