Answer:
Krypton
Explanation:
When Selenium forms an ion, it is trying to become krypton which is a noble gas.
Selenium belongs to the oxygen group on the periodic table. In this group, the atoms prefers to gain two electrons to complete their octet. When selenium gains two electrons, its octet is complete.
This will make the atom resemble krypton on the periodic table of elements.
This structure which is an octet confers a special stability on the element.
An exchange reaction consists of both synthesis and decomposition reactions.
Here’s a complex example: AB + CD → AC + BD.
Another example might be: AB + CD → AD + BC.
The answer is: hydrogen peroxide, H2O2.
H₂O₂(hydrogen peroxide) is pale blue, clear, inorganic liquid.
It is liquid because hydrogen bonds between molecules.
Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.
Because of hydrogen bonds, hydrogen peroxide has higher melting and boiling temperatures than other molecules.
Answer:
Explanation:Although the term is quite new, our connection to nature is not. We depend on nature for our survival - without healthy ecosystems, our drinking water isn’t clean nor is the air we breathe. We also enjoy nature... studies show that people who spend time in nature tend to be happier than those that don’t. It can even act as a natural anti-depressant. With industry and urban sprawl expanding at unprecedented rates, Ecosystem Services attempt to translate the benefits we receive from nature into economic terms so we can better understand the trade-offs we are making between nature and industrial development.
Answer is: <span>concentration of fluoride in the water in parts-per-million is 1 ppm.
</span>Parts-per-million (10⁻⁶) is<span> present at one-millionth of a </span>gram per gram of sample solution, f<span>or example mg/kg.
</span>m(fluoride) = 500 g · 1000 mg/g = 500000 mg.
m(water) = d(water) · V(water).
m(water) = 1 kg/L · 500000 L.
m(water) = 500000 kg.
arts-per-million = 500000 mg ÷ 500000 kg = 1 mg/kg = 1 ppm.
