Explanation:
AswerB
hydrogen, helium and lithium
It took 380,000 years for the electrons to be trapped in orbits nuclei forming the first atoms. (which is option B)
Answer:
Isotonic contractions maintain constant tension in the muscle as the muscle changes length. This can occur only when a muscle's maximal force of contraction exceeds the total load on the muscle. Isotonic muscle contractions can be either concentric (muscle shortens) or eccentric (muscle lengthens).
The answer is D all of the above
