4. Does an atom of an element always have the same number of neutrons as other atoms of the same element? Explain your answer.

Explanation:

No. Isotopes are atoms of the same element with different atomic masses (due to the different number of neutrons)

For example, carbon exists as carbon-12 and carbon-14, which both have 6 protons but have 6 and 8 neutrons respectively.

- decrease the number of plants and animals living in the water.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: