In the case of the liquid meniscus, a concave meniscus that is what one usually observes takes place when the molecules of the liquid are fascinated towards the container. This takes place with water and a glass tube. A convex meniscus takes place when the molecules exhibit a stronger attraction with each other in comparison to the container, as in the case of glass and mercury.
The shape of the liquid meniscus is determined by the relative magnitudes of the cohesive forces in the liquid and adhesive forces between the liquid and its container.
Answer:
V = 44.85 L
Explanation:
Given data:
Volume of H₂ = ?
Number of moles of H₂ = 2.0 mol
Given temperature = 273.15 K
Given pressure = 1 atm
Solution:
Formula:
PV = nRT
P = Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
By putting values,
1 atm × V = 2.0 mol × 0.0821 atm.L/ mol.K × 273.15 K
V = 44.85 atm.L / 1 atm
V = 44.85 L
Answer: half life
Explanation: Radioactive decay follows first order kinetics and the time required for the decay of a radioactive material is calculated as follows:

t= time required
k= disintegration constant
x= amount of substance left after time t
a= initial amount of substance
when one half of the sample is decayed, one half of the sample remains and t can be represented as 
at
, 


Answer:
The atoms have the same chemical symbol.