<span>The physical layers of the inner core and outer core form a single compositional layer.
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Answer: A mechanical wave is a disturbance in matter that transfers energy through the matter. A mechanical wave starts when matter is disturbed. A source of energy is needed to disturb matter and start a mechanical wave.
Does anyone know the answer?
Sr will always have 38 protons because that is its atomic number. Normally Sr has 38 protons and 49 neutrons yielding an atomic mass of 87. unless you are dealing with an isotope of Strontium in which 3 additional neutrons would give you the 53 neutrons in your answer, (38p, 52n).
I believe it becomes less dense, bc when you heat something it’s molecules spread further apart.