Table 1:
17 protons and 17 electrons
78 protons and 78 electrons
32 protons and 18 electrons
38 protons and 36 electrons
13 protons and 13 electrons
15 protons and 18 electrons
14 protons and 14 electrons
Table 2:
Ba2+ ion
Radon
Polonium
Tin
Selenium
Cesium
Magnesium Ion
IT WAS SUPER TOUGH!!!
Plankton is at the bottom of a food chain. Think of a pond. Mosquito larvae are in a pond. They eat the plankton. Small fish eat the larvae. Larger fish eat those smaller fish and the chain keeps going..BUTTT it all started with the PLANKTON. Without the plankton the whole food chain would be messed up and everything would start dying.. No plankton, no larvae, no small fish..and so on..
The correct answer is option A, that is, placer deposits.
The concentration of heavy deposits known as the placer deposits are produced by the gravitational action, generally found in streams. The minerals that take place as placer deposits comprise copper, gold, magnetite, cassiterite, and copper.
The formation of placer deposits takes place when the metal-bearing rock on land is weathered and the generated debris is washed down to the sea by the rivers. Further by the action of waves, currents, and rides the particles of heavy metal gets amassed to produce mineral sand deposits. These generally occur as beach deposits.
A situation where friction would be desirable is rubbing your hands together to make them warm in the winter time.
The answer is fixed interval
I hope that helped