Answer:
7 to 4 (higher 
)
5 to 3
3 to 2
4 to 2 (lower )
Explanation:
We can use the Rydberg formula which relates the wavelength of the photon emissions to the principle quantum numbers involved in the transition:
with 
final n, and 
initial n
evaluating for each transition:
7 to 4 
5 to 3 
4 to 2 
3 to 2 
Note that the above formula is written for 
, so lower value obtained involves higher .
So we should order from lower to higher
7 to 4 (higher )
5 to 3
3 to 2
4 to 2 (lower )
Note: Take into account that longer wavelength involves lower energy (
).
Answer:
The unknown element is Carbon.
(a) X is Carbon, its oxide is of acidic nature
(b) C+ O2 → CO2
Explanation:
We are given an unknown element that reacts with oxygen.
X + O2 → XO2
It is given that the oxide XO2 turns blue litmus red which is shown by acids, so XO2 is an acidic oxide. Also X will be a Non metal because Non metallic oxide is Acidic in nature.
The Oxide XO2 is dissolving is water. The oxide upon reacting with water will give an Acid.
XO2 type of oxide is found in the 14th group of the periodic table generally
So we have options like C, Si and Ge as these only have the Acidic oxide.
But when it comes to reactivity with water Only Carbon satisfies the need so the unknown element X is C.
CO2 + H2O → H2CO3 which is an acid.
(a) Element X is Carbon (C), The nature of the compound formed is Acidic.
(b) The reaction given will be as follows
C+ O2 → CO2
Therefore the unknown element is Carbon.
Answer:
The jewelry is 2896.54_Kg/m^3 less dense than pure silver
Explanation:
Density of jewellery = (mass of jewellery) ÷ (volume of jewellery)
=3.25g ÷ 0.428mL = 0.00325Kg÷0.000000428m^3 = 7583.46Kg/m^3
The density of silver is 10490_Kg/m^3 which is (10490 - 7583.46) 2896.54_Kg/m^3 more dense than the jewellery
The density of Silver [Ag]
The weight of Silver per cubic centimeter is 10.49 grams or the weight of silver per cubic meter is 10490 kilograms, that is the density of silver is 10490 kg/m³; at 20°C (68°F or 293.15K) at a pressure of one atmospheres.
