They are identical to the nucleus of the helium-4 atom. So the answer is helium atoms.
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Answer:
Explanation: IE1 increases from left to right across a period. However, since Na has only one valence electron, IE2 for Na involves the removal of a core electron − requiring significantly more energy.
The answer is B.
A cannot be the answer because only electrons move around the nucleus.
C cannot be it because electrons have a lot more mass than neutrons.
D can't be it because it 's not a typical occurrence for the amount of neutrons to equal the amount of electrons
Answer:
iron deficiency (anaemia)
Explanation:
when there is lack of iron it causes anaemia
