Answer:
B 144.0 s is the best answer of this question
Answer:
Atomic emission spectrum came out by a series of colored lines
Explanation:
When electricity is passing through an element or when it is viewing through a prism, a unique spectra of light emitted by an element is called atomic emission spectra. They are acting as an element of finger print because they are unique. When we are seeing a set of colored lines or a black background , it is an emission spectrum. If we are watching black lines on a colored background it is absorption spectrum. In electromagnetic spectrum the visible portion are the colors.
In nucleus electrons can exist in some areas are known as shells. Shell corresponds an energy level that is designed by a quantum number n. The lowest energy level electrons are close to the nucleus.
An atom is shone by light, its electrons absorbs photons and it gain energy, and jump to higher level.
The human gametes differ from all the other cells in the body because the somatic cells have a complete set of chromosomes
Answer: The correct answer is option B i.e., 2.78 mol
Explanation:
Aluminium reacts with iodine to form Aluminium iodide

From the equation, it is clear that 3 moles of iodine reacts with 2 moles of Aluminium to form Aluminium iodide
We know
For 2 moles of Aluminium, 
3 moles of Iodine reacts with 54 g of Aluminium
? moles of iodine react with 50 g of Aluminium