Well the multiple choices for this question would be helpful, but from my own knowledge I would say:
Magnetic fields have north and south magnetic poles.
Magnetic fields have various characteristics which includes; they originate from the north poles and flow towards the south poles, they are exhibited in the form of magnetic field lines. Magnetic fields lines never cross one another,they all have the same strength and seek the path of least resistance between opposite magnetic poles etc.
the element chlorine is represented by the symbol Cl
It makes the concentration of protons higher outside of the membrane than the inside
Answer:
group 1 - cations charge +1
group 7 - anions charge -1
Explanation:
Group 1 has one valence electron and will lose one electron to complete the octet.
Group 7 has 7 valence electrons and will accept an electron to complete the octet.
Elements 2 and 4 is the answer