"outside visible spectrum" would be the right way to define the power of the goggles provided to the soldiers to see at night. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer comes to your great help.
Answer:
The answer is A
Explanation:
That is the only answer that even remotely resembles an ultrasound hope this answered your question.
While staying in the same period, if we move from left to right across the period, the atomic radius decreases. The reason is, in a period the number of shells remain the same and the number of electrons and protons increase as we move across the period to the right. The increased electrons and protons attract each other with greater force and hence the atomic size decreases.
So the element on the left most will have the largest atomic radius. So the correct ans is Potassium. Potassium will have the largest atomic size among Potassium, Calcium and Scandium.