He was working with electrons
When two air masses meet together, the boundary between the two is called a weather front. At a front, the two air masses have different densities, based on temperature, and do not easily mix. One air mass is lifted above the other, creating a low pressure zone.
Mg is an element that stands for Magnesium.
Mg is the chemical symbol for Magnesium.
HCl is considered as polar molecule and that is incorrect answer, The choices provided are A) HCl , B) CH₄ , C) H₂O, D) NH₃
And the correct answer is : B) CH₄
In case of H₂O and NH₃ the high difference in electronegativity between nitrogen or oxygen and hydrogen make the bonds acquire partial charges and become polar while in case of CH₄ the difference in electronegativity between carbon and hydrogen is only 0.4 so it considered as non-polar bond
also carbon connected from all directions with Hydrogens