Answer:
2-
Explanation:
For an element to be stable, it must follow the octet rule: an atom will gain, lose or share electrons until its valence shell is complete with 8 electrons.
An element with the valence electron configuration ns²np⁴ has 6 (2+4) electrons in its valence shell. Thus, in order to fulfill the octet, it will gain 2 electrons. As a consequence, it will form an anion with charge 2-.
Since you forgot to include the choices for classification, I would just define each of these and tell you the hints that would help you classify them.
Among these acids and bases, its is the strong acids and strong bases that are easily classified. You should note that there are only 7 strong acids existing. All the rest are weak acids. These 7 acids are: HCl, HBr, HI, HClO₃, HClO₄, HNO₃ and H₂SO₄. On the other hand, there are only 8 strong bases; the rest are weak bases. These are the hydroxides of the Group ! and !! metals: LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)₂, Sr(OH)₂, and Br(OH)₂.
For the weak acids and weak bases, just remember the definitions of Arrhenius, Lewis and Bronsted-Lowry. A weak base are those compounds that accept H⁺ protons, produce OH⁻ ions when solvated and an electron donor. A weak acid are those compounds that donate H⁺ protons, produce H⁺ ions when solvated and an electron acceptor.
The wistle is coming from all the chemicals including the fire you use to light the firework and a chemcial reaction is occuring which is the sound that is made because of this
<span>Population growth is limited in ecosystems because of lack of resources. If there were unlimited resources, a population would grow exponentially.
For example, if a single bacterium were placed in a petri dish and was given unlimited resources, it would multiply to cover the entire world within several days.
Unfortunately, resources are limited, so populations are too.</span>
If the density is higher than water than the object will sink
