<span>The student is incorrect because helium has 2 valence electrons and it's in group 18 because the first energy level is full. Although helium is placed in Group 18 which generally has 8 valence electrons, it does not have 8 valence electrons as the student suggested. It was grouped together with the noble gases because it exhibits similar properties with them. </span>
Answer:
protons and neutrons
Explanation:
The nucleus of the atom contains protons and neutrons. The electrons of the atom orbit the nucleus.
Answer:
Magnesium chloride/Molar mass
95.211 g/mol
Explanation:
Answer:
Explanation:
All of above except carbon dioxide
Answer:
La radiación UV-B es parcialmente absorbida por el ozono y llega a la superficie de la tierra, produciendo daño en la piel. Ello se ve agravado por el agujero de ozono que se produce en los polos del planeta.
Explanation:
