One is the plum pudding theory by Thomsons that theorized that positive and negative charges were randomly distributed in an atom. This was later discovered that the positive charge was located at the small nucleus center of the atoms and negative electrons on the outside.
Another is the aspect in Bohr model theory that electron orbit the nucleus like planets orbit the sun. Quantum mechanisms have come to disprove this and identify that electron orbit can only be predicted by probabilities and not in the certainty of their position around the nucleus of the atom. They randomly skip and hop (disappear and reappear) at positions around the nucleus.
Answer:
You may know the formula of calcium chloride (is:-CaCl2)
So.
CaCl2 ⇄ Ca-²+2Cl-¹
1mole⇄1mole+2moles
So from above ..
1mole CaCl2 produce 1mole Ca-² & 2 moles of Cl-².
For 2.5 moles we multiply the above chemical eq. With 2.5
2.5CaCl2⇄2.5Ca-²+5Cl-¹
So from 2.5 moles of CaCl2 we get 2.5 mole calcium ion and 5 moles chloride ion…
Explanation:
Answer:: A photovoltaic cell converts light into electrical energy. Suppose a certain photovoltaic cell is only 63.5% efficient, in other words, that 63.5% of the light energy is ultimately recovered. If the energy output of this cell is used to heat water, how many 520 nm photons must be absorbed by the photovoltaic cell in order .
Explanation:
<span>Answer:
pH = 2.7, therefore amount of H+ needed is 10^-2.7 M
u haf 80 ml of hcl and 90 ml of naoh left, therefore 20 ml of hcl used, and 10ml of naoh used.
mols of H+ = 0.02 x 7 x 10^-2 = 1.4 x 10^-3
mols of OH- = 0.01 x 5 x 10^-2 = 5 x 10^-4
H+ and OH- neutralise each other, so remaining mols of H+ = 9 x 10^-4
u need 10^-2.7 mols of H+, so 10^-2.7 - 9 x 10^-4 = 0.001095 mol
vol of HCL needed = 0.001095 / 7 x 10^-2 = 0.0156 L = 15.6 mL</span>