Answer:
14.77 mol.
Explanation:
- It is known that every 1.0 mole of compound or element contains Avogadro's number (6.022 x 10²³) of molecules or atoms.
<u><em>Using cross multiplication:</em></u>
1.0 mole of He contains → 6.022 x 10²³ atoms.
??? mole of He contains → 8.84 x 10²⁴ atoms.
<em>∴ The no. of moles of He contains (8.84 x 10²⁴ atoms) </em>= (1.0 mol)(8.84 x 10²⁴ atoms)/(6.022 x 10²³ atoms) =<em> 14.77 mol.</em>
How is the hydrosphere changing? Human contributions to greenhouse gases in the atmosphere are warming the earth's surface - a process which is projected to increase evaporation of surface water and accelerate the hydrologic cycle. In turn, a warmer atmosphere can hold more water vapor.
Answer:
Alkali metal hydroxides can be used to test the identity of metals in certain salts. The colour of the precipitate will help identify the metal : Calcium hydroxide is soluble; no precipitate is formed.
Answer:
state of matter
Explanation:
so take water for example, water has a melting point and a boiling point right? So if it's below 0 degrees, then it's in its solid phase. If the temperature is above 0 degrees, then the water starts to melt into its liquid phase. Then when the temperature is above 100 degrees, water starts to boil and become its gas phase. This is the same for all substances. The only difference is different substances have different melting and boiling points so the numbers will be different depending on your substance. hope this helped!
Molar mass of sodium=23g
2 mole sodium gives 2 g H2
i.e 46g sodium gives 2g H2
so 65.4g will give=2.84g H2
now no. of molecules = 2.8/2*avogadros number
