An atom with a mass number of 61 amu has 33 neutrons in its nucleus.
What element is this ?

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Explanation:

amu = atomic mass unit

If the amu is 61, and we have 33 neutrons, then there are 61-33 = 28 protons. The number of protons directly determines the element. Use the periodic table to find that the element Nickel (symbol "Ni") has 28 protons. The number up top shows the number of protons. For some periodic tables, the number down below (some decimal value) represents the atomic mass. This is usually the average atomic mass when considering all varieties of isotopes.

Nickel is a transition metal found in the middle portion of the periodic table, in the top-most row. It has Cobalt (Co) on the left side, Copper (Cu) on the right side, and Palladium (Pd) below it. See the diagram below.

i think its

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia