To know the right answer,. let us define each of the following choices.
1. Isotope is a group of atoms that belong to same element but differ on their mass numbers. As written in the periodic table, each element has a specific value of atomic numbers which represent the number of protons in the atom. But they may differ when it comes to the number of neutrons in the nucleus.
2. Compound is a combination of at least two elements together that are bonded by intermolecular forces like ionic or covalent bonding, electrostatic forces and London dispersion forces.
3. Water is a compound made up of two hydrogen atoms and one oxygen atom.
4. Ions are atoms of elements that are not neutral because they readily accep ot gain electrons from other elements. So, they exist as cations (positively charge ions) or anions (negatively charge ions).
Basing on the descriptions of each choice, the answer to the description of atoms with an electrical charge is an ion.
The correct answer is option B. X-rays are the waves found in the electromagnetic spectrum at a wavelength of 1x10^-11 - 1x10^-8 m and frequencies of 3x10^16 to 3x10^19 Hz. These waves penetrate easily through certain materials which made them usefule in the field of medicine.
In a voltaic cell (one that happens spontaneously), electrons flow from a negative electrode to a positive electrode (anode cathode). The reaction that happens is a redox reaction where the anode is oxidized (goes from a solid to an ion) and the cathode is reduced (going from an ion to a solid).
