We Know that Number of Protons in an Element's Atom Indicates the Atomic Number of the Element.
Given : The Atom of Element A has 11 Protons
⇒ The Atomic Number of Element A is 11
Hz is the measurement of a frequency equal to one cycle per second. since this wave shows 9 peaks and valleys or "cycles" your answer would be 3 Hz due to the fact that the length of time is 3 seconds. (3 cycles per second X 3 seconds.)
Answer:
I think its the first one
Explanation: