One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles.
Answer:
when the substance is decrease
Explanation:
Answer: Option (a) is the correct answer.
Explanation:
It is known that elements which have completely filled octet when they are present in neutral state then they do not need to gain or lose an electron. Hence, the element becomes unreactive in nature.
For example, neon is a noble gas whose atomic number is 10 and its electronic distribution is 2, 8. As they have completely filled orbitals so they do not react with other elements.
As a result, they are rarely found in combination with other elements.
Thus, we can conclude that the Group 8A(18) elements are unreactive and are rarely found in combination with other elements.
Answer;
H- (negatively charged hydrogen ion)
Explanation;
The hydrogen ion has the same electron configuration as an atom of Helium. -Hydrogen ion is formed when a hydrogen atom loses or gains an electron. A positively charged ion is formed when hydrogen atom loses an electron (remaining with zero electrons) while a negatively charged ion (H-) is formed when a hydrogen atom gains an electron thus having 2 electrons.
-Helium atom has two electrons, therefore, it is similar with an negatively charged hydrogen.
