<span> I'll try. A purely ionic bond, as the name implies is a bond between ions. If that sounds like double-talk it's because some ionic compounds are more ionic than others. A purely covalent compound is one in which the electrons are shared EQUALLY. It turns out that the only compounds in which the electrons are shared equally is one in which both atoms sharing the electrons are of the same element. For example O2, N2, Cl2, I2 or F2. Now suppose you make a compound between Fluorine and Iodine, IF. Since fluorine has a greater attraction for electrons than iodine, the bond will be polar. That is the fluorine part of the molecule will be negative and the iodine part will be positive. The attraction for electrons isn't equal. The same thing happens with ionic bonds. In your first question, the ionic character decreases from NaF through SiF4. Sodium loses an electron quite readily because it achieves a stable neon like configuration. Fluorine attracts an electron very strongly for the same reason. But as you move across the period, two things are happening. First, look at SiF4. Silicon is right in the middle of the period, It can achieve a stable inert gas configuration either by gaining 4 or losing 4 electrons. So it depends upon the electronegativity (the electron grabbing ability) of the atom it's combining with. Since Fluorine has the highest electron grabbing ability of any of the reactive elements, it will tend to pull the electrons away from silicon. But silicon doesn't completely give them up as it would in a purely ionic compound. AlF3 is similar but will tend to give up 3 electrons a little easier than SiF4. MgF2 is even more ionic because it's approaching an inert gas configuration and only need to lose 2 electrons. Can you see what's happening? The closer you get to the middle of a period, the less likely an atom is to give up COMPLETELY its electrons. In question 2 your answer is CO. The elements are close together (which means that their electronic structure is similar) and carbon, like silicon is in the middle of the period so its more likely to share electrons than it is to give them up (form an ionic bond). So it turns out that most chemical bonds are neither completely ionic or covalent but lie in between the two extremes and are called polar covalent. I hope this helps.</span>
Answer:
oxygen is a present in our atmosphere and mixed with other gases on the surrounding screen plants are also measure source of getting oxygen they take carbon dioxide from making their food by for the cities and give away oxygen in return
Explanation:
most of the earth oxygen comes from tiny Ocean plants are called phytoplaston
It is a scientific hypothesis. A scientific hypothesis must be testable, however there is a significantly more grounded necessity that a testable speculation must meet before it can truly be viewed as logical. This foundation comes essentially from crafted by the rationalist of science Karl Popper, and is called "falsifiability".
<u>Given:</u>
Concentration of HNO3 = 7.50 M
% dissociation of HNO3 = 33%
<u>To determine:</u>
The Ka of HNO3
<u>Explanation:</u>
Based on the given data
[H+] = [NO3-] = 33%[HNO3] = 0.33*7.50 = 2.48 M
The dissociation equilibrium is-
HNO3 ↔ H+ + NO3-
I 7.50 0 0
C -2.48 +2.48 +2.48
E 5.02 2.48 2.48
Ka = [H+][NO3-]/HNO3 = (2.48)²/5.02 = 1.23
Ans: Ka for HNO3 = 1.23
In an ecosystem, the only true producers are autotrophic organisms like plants and bacteria. These organisms produce energy by converting the energy from the sun into simple sugars.
All of the other organisms in the food chain, like the fruit fly, are simply consuming the energy produced by the plants/bacteria and not actually making/producing energy from a new source.
