This is kind of hard to show without the picture, but to make an ionic bond with Na and Fl you would have the sodium move an electron to the fluorine, so the answer is C! This is because of the fact that sodium has an outer shell valance electron (so it's unstable) and the fluorine would accept that because it is missing an electron in the outer shell. So this sharing would lead to the bond being created!
<span>Geologists generally know the age of a rock by determining the age of the group of rocks, or formation, that it is found in. The age of formations is marked on a geologic calendar known as the geologic time scale. Development of the geologic time scale and dating of formations and rocks relies upon two fundamentally different ways of telling time: relative and absolute.</span>
The choice is D - both A and C
Answer:
the environment and parasites
The right option is a. contour interval
The difference in elevation between the highest and lowest contour lines on a topographical map is called contour interval.
A contour interval is the vertical distance between the two contour lines (highest and lowest) in a topographical map. The contour interval is usually stated explicitly on the right-hand lower part in every map. 20 feet for a 1:24,000 map scale is the frequently used contour interval and different contour intervals is available for different maps.
