Answer:
The correct option is A
Explanation:
Water from a river is used for many activities in a community. These activities could include (but not limited to) tourism, drinking for animals, local transport, irrigation for nearby farming, recreation (as in swimming), habitat for some living organisms among others. Rivers are not limited by what limits the influence of oceans such as taste (it's saltiness, which cannot be used in farming also) and wave current.
Answer: when two elements combine, A and B, the ratio of the weight of B combining with A is always a whole number
Explanation:
<span>increase while moving left to right within a period and increase while moving upward within a group. </span>
A. Large atoms have valence electrons farther from the nucleus and lose them more readily, so they are more reactive than small atoms.
For example, the valence electron of a small atom like Li is tightly held. <em>Lithium gently fizzes</em> on the surface as it reacts with the water to produce hydrogen.
In contrast, the valence electron of a large atom like Cs is so loosely held that <em>cesium exlodes </em>on contact with water.