They are all correct good job bud I hope it helps and good luck
<span>Calcitriol </span>is the active form of vitamin D. (D)
Fluoride and calcium are both helpful for stopping tooth decay
Answer:
A Neutron and a Hydrogen Atom
Explanation:
Hydrogen atom having an atomic mass of 1.008 amu consists of one proton and one electron. Hence, the +ve and -ve charges cancels out and makes the hydrogen atom a neutral specie.
Also, we know that neutron is neutral sub particle while, proton and electron are positively and negatively charged respectively. Therefore, a neutral neutron having no charge becomes equal to hydrogen atom having zero charge due to cancellation of both +ve and -ve charges.
Answer: The correct answer is option B.
Explanation: There are 7 elements in group VIII-A. They are Helium (He), Neon(Ne), Argon(Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo). They are considered as a part of group 18.
Metals are shown in purple color in the periodic table. Metalloids as blue color and Non-metals are shown in green color.
Group VIII-A elements have fully filled orbitals and hence are most stable amongst all the elements in the periodic table. They are considered as least reactive elements and as they are categorized as non-metals. So, they are the least reactive non-metals.
Therefore, the correct option is B.