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.
A converging lens made from a transparent plastic bottle filled with water is used to enable Pak Dollah read the newspaper.
<h3>What is long-sightedness?</h3>
Long-sightedness is an eye effect in which objects are not able to focus on the retina but behind the retina, therefore, near objects are not clearly seen except they are placed far away.
To correct long-sightedness, a suitable converging lens is used to bring the image to focus on the retina.
To construct a converging lens for Pak Dollah, the transparent plastic bottle is filled with water to serve as a converging lens and Pal Dollah will read through it.
Therefore, a converging lens made from a transparent plastic bottle filled with water is used to enable Pak Dollah read the newspaper.
Learn more about long-sightedness at:brainly.com/question/4419161
Answer is: d. Mg3N2.
Mg₃N₂ is magnesium nitride.
Nitrogen (nonmetal) in this chemical compound has oxidation number -3 and magnesium (metal) has oxidation number +2.
Smallest common multiple for 3 and 2 is 6.
number of nitrogen atoms = 6 ÷ 3.
number of nitrogen atoms = 2, there are two nitrogen atoms.
number of magnesium atoms: 6 ÷ 2.
number of magnesium atoms = 3.
If bubbles aren't a for sure way of knowing a chemical reaction I don't know what is. But being for real, it is a chemical change because the bubbles are releasing carbon dioxide meaning it turned into a product from a reaction with outside forces.