Answer:
n₁ = 1.0× 10⁻⁴ mol
Explanation:
Given data:
Initial volume of balloon = 230 mL
Initial number of moles of He =?
Final number of moles of He = 3.8 × 10⁻⁴ mol
Final volume of balloon = 860 mL
Solution:
The given problem will be solve through Avogadro law,
"Number of moles of gas and volume are directly proportional to each other at constant temperature and constant pressure"
Mathematical relationship:
V₁/n₁ = V₂/n₂
No we will put the values.
230 mL /n₁ = 860 mL/ 3.8 × 10⁻⁴ mol
n₁ = 230 mL× 3.8 × 10⁻⁴ mol/ 860 mL
n₁ = 874 × 10⁻⁴ mol. mL / 860 mL
n₁ = 1.0× 10⁻⁴ mol
Answer: a) 
b) 
Explanation: Visible light is a form of electromagnetic wave.
Wavelength is defined as the distance between two successive crests of a wave. It is represented as symbol
.
Frequency is defined as the number of complete cycles happening per second. It is represented by the symbol
.
Wavelength and Frequency follow inverse relation,

where, c = speed of light = 
Wavelength and frequency of a wave is usually expressed in a range.
a) 
b) 
Answer:<em> A transfer of electrons occurs when fluorine and calcium react to form an ionic compound. This is because calcium is in group two and so forms ions with a two positive charge. ... A pairs of shared electrons makes one covalent bond. The compound formed is known as a molecule***</em>