Answer:
that's because....
group 1 (e.g Na, K) those tend to lose one electron to gain noble gas electron configuration.
they can achieve that by just losing one electron from their outer shell.
as you go down the group 1, element gets bigger in size, which means there is more space between nucleus (which is in center of atom) and electron of outer shell. the more far away they are the less attraction force between them.
so its easier for potassuim to lose one electron than for lithuim.
so that means potassium will easily give up 1 electron to react with non metal or other element therefore it is more reactive than lithuim
but in case of non metal, the opposite happens but simple to understand.
as you go down the group 7 (halogen- Cl, Br, I) element will get bigger therefore force between nucleus and outer electron is getting smaller. they have to gain 1 electron in order to fill the outer shell (to gain noble gas electron configuration.)
as florine is more smaller in size than clorine it is more reactive because florine has more tendency to pull extra electron from metal or other element towards its side. so it easily gain 1 electron to react.
The average atomic mass if the element above is calculated by the sum of the product of the isotope abundance and its atomic mass unit. It is expressed as:
Average atomic mass = Σ xi(Mi)
<span>Average atomic mass = (.7547 x 248.7) + (.2453 x 249.4) = 248.87
</span>
Hope this helps.
Answer:
95,000 centigrams
Explanation:
There is 1000 CG in 0.01 kilograms
so you do 1000*95 which equals 95,000 centigrams.
The mass of Copper electroplated is 68.76 g
<h3>What is electroplating?</h3>
The process of plating a metal onto another is known as electroplating.
It is often used to prevent corrosion of metal or for the decorative purposes
In this process, electric current is passed through an aqueous solution containing dissolved cations.
The dissolved cations are reduced developing a thin metal coating on the electrode.
At cathode,

Current, I = 14.5 A
Time, t = 4 hrs = 4×60×60 = 14400 sec
Charge, q = It = 14.5×14400= 208800 C
Copper metal deposited by 2×96487 C = 63.55 g
Copper metal deposited by 208800 C = 
= 68.76g
Hence, The mass of Copper electroplated is 68.76 g
Learn more about electroplating:
brainly.com/question/22104403
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