<span>B is the correct answer. Carbon dioxide is a compound of two elements, carbon and oxygen. There are two oxygen molecules for every carbon molecule in the compound. </span>
It is important because you need vitamins and minerals from them e.g. Scurvy no vitamin c
Answer:
Similarities: both are chemical messengers, both can have (but don't necessarily have) similar structures (made from amino acids), both can be produced by the central nervous system (hypothalamus produces some hormones), certain molecules can act as both hormones and neurotransmitters (example: norepinephrine).
Differences: neurotransmitters are released by neurons across a synaptic gap, have very short distances to travel, and act very quickly on the neighboring cell. Hormones are released by glands and often have to travel longer distances, which means that they are slower-acting. Also, hormones are typically used for regulation (negative feedback) while neurotransmitters are used for stimulation of a neighboring cell.
Explanation:
Answer:
15
Explanation:
the atomic number is the number above the symbol. the number below is the atomic mass.
Answer: Ice cores.
Explanation: Ice cores are commonly studied by scientists to find out what the climate was like decades and centuries ago.
