Answer:
No photoelectric effect is observed for Mercury.
Explanation:
From E= hf
h= Plank's constant
f= frequency of incident light
Threshold Frequency of mercury= 435×10^3/ 6.6×10^-34 × 6.02×10^23
f= 11×10^14 Hz
The highest frequency of visible light is 7.5×10^14. This is clearly less than the threshold frequency of mercury hence no electron is emitted from the mercury surface
Answer:
See Explanation
Explanation:
According to the question, it is established that the pain caused by a lot of insect bites owes to the acidity of the insect bites.
If this is true, then there is an urgent need to neutralize the acidic insect bite using a basic substance.
Hence the pH of the creams used to treat insect bites should be basic(having a high pH).
2. The compound methene can not exist because it is supposed to be derived from the alkane called methane which contains only one carbon atom.
In order to form an alkene, there must be a double bond between two carbon atoms. This is not possible because there is only one carbon atom in the hypothetical methene. Hence, a compound named methene cannot exist.
Below is an attachment of the Lewis structure with the lowest formal charges.
The formal charge is the fictitious charge that an atom in a molecule would have if the electrons in the bonds were evenly distributed among the atoms. The nonbonding electrons on a neutral atom are subtracted from its valence electron count, which is then followed by the number of bonds that bind it to other atoms in the Lewis structure, to get the formal charge. This is another way to put it. When hyponitrous acid is oxidized in the atmosphere, nitric and nitrous acids are produced. By reducing a nitrate or nitrite by sodium amalgam in the presence of water, hyponitrite salts have been created.
Learn more about formal charge here-
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H ( hydrogen ) is the answer I believe.
%yield = 88.5%
<h3>Further explanation</h3>
Given
Reaction
Cu(s) + 2 AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s)
Required
The percent yield
Solution
mol AgNO₃(MW=169,87 g/mol) :
= mass : MW
= 127 : 169.87
= 0.748
mol Ag from equation :
= 2/2 x mol AgNO₃
= 2/2 x 0.748
= 0.748
Mass Ag (theoretical) :
= mol x Ar Ag
= 0.748 x 108
= 80.784
% yield = (actual/theoretical) x 100%
%yield = 71.5/80.784 x 100%
<em>%yield = 88.5%</em>