Explanation:
When an electromagnetic wave like light hits a material, the electrons gets emitted. The emission of electrons is called photoelectric effect. The emitted electrons are called photoelectrons. In this process the transfer of energy takes place from light to an electron.
Hence, the correct option regarding the photoelectric experiment is (A) " Light can cause electrons to be released from the surface of a metal."
Answer:-
KOH determines how much Mg(OH)2 is made.
2 mol of Mg(OH)2 formed
Explanation:-
The balanced equation is
MgCl2 + 2KOH --> Mg(OH)2+ 2KCI,
From seeing the coefficients we notice
2 mol of KOH reacts with 1 mol of MgCl2
4 mol of KOH reacts with 1 x 4 / 2 = 2 mol of MgCl2
3 moles of MgCl2 was added but only 2 mol react.
So we see there is excess MgCl2 .
Hence KOH is the limiting reactant.
So KOH determines how much Mg(OH)2 is made.
We see from the balanced chemical equation,
2 mol of KOH gives 1 mol of Mg(OH)2.
4 mol of KOH will give 1 x 4 /2 = 2 mol of Mg(OH)2.
Answer:
pH = 6.5
Explanation:
Given data:
pH of substance = ?
[OH⁻] concentration = 3.2×10⁻⁸
Solution:
pOH = -log[OH⁻]
pOH = -log[3.2×10⁻⁸]
pOH = 7.5
we know that,
pH + pOH = 14
pH = 14- pOH
pH = 14 - 7.5
pH = 6.5
Answer:
<h2>
</h2>
Explanation:
According to hooks law "provide the elastic limit of an elastic material is not exceeded the extension e is directly proportional to the applied force F"
where F= applied force
k= spring constant
e= extension
Given data
length of string l = 16cm
extension e = 20-16= 4cm
applied force = 5N
we need t o first calculate the spring constant k
apply the formula
we can now calculate the extension of the string when supporting a 6N weight
The length of the string when supporting a 6N weight is
<em>COMMENT </em><em>:According to the analysis an extra weight of 1N will cause add 0.8cm to the length of the string</em>
