Answer: v = 2π2 Kme2 Z / nh
Explanation:
The formula for velocity of an electron in the nth orbit is given as,
v = 2π2 Kme2 Z / nh
v = velocity
K = 1/(4πε0)
m= mass of an electron
e = Charge on an electron
Z= atomic number
h= Planck’s constant
n is a positive integer.
1.39 g HCl
Explanation:
The balanced chemical equation for this reaction is given by
Zn(<em>s</em>) + 2HCl(<em>aq</em>) ---> ZnCl2(<em>aq</em>) + H2(<em>g</em>)
Convert the # of grams of Zn to moles:
1.25 g Zn × (1 mol Zn/65.38 g Zn) = 0.0191 mol Zn
Use the molar ratio to find the # of moles of HCl needed to react completely with the given amount of Zn:
0.0191 mol Zn × (2 mol HCl/1 mol Zn) = 0.0382 mol HCl
Convert this amount to grams:
0.0382 mol HCl × (36.458 g HCl/1 mol HCl) = 1.39 g HCl
The coins in 1991 had more copper in them compared to the coins today. So, that is why it worth 3.3p.
<span>oxygen is a mixture and a rock is a pure substance.</span>
The alkali metals are lithium, sodium, potassium, rubidium, cesium and francium, and the alkaline earth metals are beryllium, magnesium, calcium, strontium, barium and radium. Hydrogen is placed on the periodic table<span> above </span>group<span> 1a but is not considered part of the </span>group<span>.
Refer to: </span>https://www.reference.com/.../group-1a-group-2a-elements-common-94c6bc654f3d5a4...
