Answer:
there are 20 oxygen atoms in 4.00 moles of Dinitrogen pentoxide
Explanation:
there are 2 atoms in an oxygen molecule , so each oxygen molecules has at least 2. Dinitrogen pentoxide is N2O5, which has 7 atoms, 2 nitrogen and 5 oxygen. 1 molecule of N2O5 has 5 oxygen atoms, so 4 of then would be 20
Answer:
Magnesium and calcium belong to the second group i. e. alkaline earth metals. They are known as earth metals because they are extracted from the earth. They are very reactive elements. Their reactivity increases when we go from top to bottom because the outermost electrons goes farther from the nucleus i. e. atomic radius increases so less energy is needed for its removal.
Answer:
John Dalton
Explanation:
John Dalton (1766-1844) is the scientist credited for proposing the atomic theory. This theory explains several concepts that are relevant in the observable world.
"The angle at which light hits a reflecting surface is called the angle of incidence, and the angle at which light bounces off a reflecting surface is called the angle of reflection."
ANSWER
An atom of element is electrically neutral because the number of positive protons are equal to number of negative electrons.