Answer:
Explanation:
The net force on electron is electrostatic force between electron and proton in the nucleus .
Fc = 
This provides the centripetal force for the circular path of electron around the nucleus .
Centripetal force required = 
So
What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
<h3><u>Answer;</u></h3>
exceeds evaporation over land
Precipitation<u> exceeds evaporation over land </u>
<h3><u>Explanation;</u></h3>
- <em><u>In order to maintain earths water balance, evaporation exceeds precipitation over oceans but precipitation exceeds evaporation over land.</u></em>
- Water evaporates into the atmosphere from the ocean and to a much lesser extent from the continents. Winds transport this moisture-laden air, often great distances, until conditions cause the moisture to condense into clouds and to precipitate and fall.
- Most precipitation originates by evaporation from the oceans. Over time, water evaporated from the oceans is replenished by inflow of freshwater from rivers and streams.
Answer:
X 86 206
Explanation:
Radioactive atoms are nuclei that can under go disintegration to emit either an alpha particle, beta particle or gamma radiation. The process could be spontaneous or stimulated.
When a radioactive atom R 88 210 emits alpha particle, it would produce an element with atomic number 86 and mass number 206 i.e X 86 206. An alpha particle is usually a helium nucleus.
⇒ 
+ 
+ energy
D. It has almost no hydrogen ions, therefore it is very basic.
