Answer: option <span>A) increases from bottom to top within the group.
Explanation:
</span>It is a known trend that the metallic character of the elements increase from let to right and from top to bottom.
The greater the metallic character the greater the reactivity of the metal.
So, the elements of the columns 1 and 2 are the most reactive metals and among them the elements at the bottom are yet more reactive.
<span>The higher reactivity of the metals that are lower in the periodic table is attributed to the greater total number of electrons.
The greater the total number of electrons the more reactive the metals
as their outermost electrons (the valence electrons which are those that react) are located further from the nucleus and therefore they are held less
strongly, which makes them react more easily.</span>
Explanation:
The reaction equation will be as follows.
Hence, moles of Na = moles of electron used
Therefore, calculate the number of moles of sodium as follows.
No. of moles = 
= 
(as 1 kg = 1000 g)
= 195.65 mol
As, Q = 
where F = Faraday's constant
= 
= 
mol C
Relation between electrical energy and Q is as follows.
E = 
Hence, putting the given values into the above formula and then calculate the value of electricity as follows.
E =
= 
= 
As 1 J = 
kWh
Hence, 
kWh
= 3.39 kWh
Thus, we can conclude that 3.39 kilowatt-hours of electricity is required in the given situation.
Answer:
if the object sank then that object has a greater density then water. if the object floated then its density is lower then water.
Explanation:
lets say object 1 has a density of 24/cm3. the density is greater then water (1.0000g/cm3) so it would sink. now lets say object 2 has a density of 0.79383g/cm3 since it's less then the density of water (1.0000g/cm3) it would float.
Advantages of using tidal energy:
-Environment-friendly
-A highly predictable energy source
-High energy density
-Operational and maintenance costs are low
-An inexhaustible source of energy
Disadvantages of using tidal energy:
-High tidal power plant construction costs.
-Negative influence on marine life forms.
-Location limits.
-The variable intensity of sea waves.
Answer:
Write down the phases and what happens during each phase.
Explanation:
