According to the Big Bang theory, the universe was once very dense and is now expanding.
Evidence supporting the Big Bang theory includes the presence of cosmic microwave background radiation, visual observation of redshifted objects and the abundance of primordial elements found throughout the universe.
Answer:
1) NH3->Product
2) NH4->Reactant
Explanation:
Reactants are the substances in with you start the chemical reaction with (before the arrow)
Products are the result (after the arrow)
Answer:
By action potential nerve contract the muscle
Explanation:
The muscle contract when the nervous system sends action potential to the muscle. So the nervous system delivers signal to muscle, the first signal reaches the neuromuscular junction. The signals are passed by a chemical messenger called neurotransmitter release by motor neurons, the chemicals bring reaction and shorten the muscle fibre. When neurotransmitter are absent or reduce in concentration the process reverse and muscle relax again.
