Answer:
key concepts and summary. When electrons move from a higher energy level to a lower one, photons are emitted, and an emission line can be seen in the spectrum. Absorption lines are seen when electrons absorb photons and move to higher energy levels
Explanation:
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A. phase changing. Physical change is any change in matter that involves the substance going from one physical state to another, and phase change is most commonly used to describe transitions between solid, liquid and gaseous states of matter.
Answer:
Question: A patient is diagnosed with a damage in the thyroid gland.
Which isotope is used to treat the patient?
Option:
A. Copper-64
B. Cobalt-60
C. Carbon-14
D. Iodine-131
Correct answer : D. Iodine-131
Question: Give the definition of isotopes.
Answer : Isotopes is the atoms of elements with the same proton number but different number of neutrons.
It's because they add to its hardness . Calcium is naturally dissolved in water
