Answer:
0
Explanation:
An image of the lewis structure of the compound OF2 is shown in the image attached.
A Lewis structure is a structure in which electron pairs on atoms are shown as dots. Sometimes shared electron pairs are shown by a horizontal straight line connecting the two atoms involved.
OF2 has no double bonds as shown in its structure. It is a compound containing only two O-F sigma bonds and no pi-bonds.
Answer:
Alkali metals
Explanation:
The alkali metals are a group of metallic elements which are present in the first group of the periodic table. In other words, they are present in group 1 of the periodic table. These elements have one electron in their valence shell, the reason why they are placed in group 1.
They ionize by losing one electron to achieve the configuration of the nearest Noble gas or inert gas. Because they need to offset only one electron in their outermost shell, they are very chemically reactive and hence rarely occur in the free state.
Examples of elements in this group include lithium, potassium and sodium. They each have one electron only in their outermost shells.
C. Melting ice.
It is C because melting ice is a change of state from solid to liquid which requires an addition of energy(or entropy) into the system.
Condensation of water occurs from a gas to a liquid state, which takes energy out of the system(water) and gives it to the surroundings(air around it). Freezing water is the same as condensation except for the state change. Deposition is simply gas to a solid instantaneously so you can again see it as with the other two examples.