In this question, you are asked to find two condition which was:
1. Same phase at STP( standard temperature and pressure)
2. Different structure and properties
In option 1 and 4 the phase of the element is different. It was solid+gas for option 1 and solid+liquid for option 4. That clearly not fulfills the first condition.
At STP helium is gas but mercury should be liquid, not gas. That means option 3 won't fulfill the 1st condition too.
Option 2 is true since both of them gas and their structure and properties are different. One example of properties is that oxygen doesn't have an odor but ozone has.
Bromine atoms usually end up with SEVEN valence electrons.
Bromine belongs to group 17 i.e. halogen group. Its atomic number is 35. The electron configuration of Bromine is 1s² 2s²2p⁶ 3s²3p⁶ 4s²3d¹⁰4p⁵. In the last shell, we see 4s²4p⁵, thus 2+5 = 7 valence electrons are present.
<span>we know that each
element has an unique spectra and it can be used to identify the
element. it shows that the energy levels of the electrons and different colors are the result of different wavelengths.
hope it helps
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Here we have to get the moles of water generated by the combustion of vitamin C.
4 moles of water (H₂O) will generate from the combustion of vitamin C.
The vitamin C is the ascorbic acid having the molecular formula C₆H₈O₆. On decomposition it produces water (H₂O) and carbon di oxide (CO₂).
The molecular weight of ascorbic acid is 176.12 g/mole.
In this analysis 0.163g of H₂O produces from 0.400g of vitamin C.
Thus from 176.12 g of vitamin C ×176.12 = 71.768 g of H₂O will produce.
The molecular weight of H₂O is 18 g/mole. Thus 71.768 g is equivalent to = 3.98 ≅ 4
Thus 1 mole of vitamin C (ascorbic acid) produces 4 moles of water on combustion.
The balanced combustion [in presence of excess oxygen (O₂)] reaction can be written as- C₆H₈O₆ + 5O₂ = 4H₂O + 6CO₂.
Thus the moles of water generated from combustion of vitamin C is determined.
Taking into account the definition of density, the density of the cubic block of ice is 1.077
In first place, density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.
In other words, density is the relationship between the mass of a substance (or a body) and its volume. It is an intrinsic property of matter, since it does not depend on the amount of substance that is considered.
The expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
In this case, you know:
- mass= 1400 grams
- volume= 1300 cm³
Replacing in the definition of density:
Solving:
density= 1.077
Finally, the density of the cubic block of ice is 1.077
Learn more about density: