Answer:
Explanation:
Given :
Mass of a bar of lead = 115.2 g
Initial water level 
= 25 mL
Final water level = 35.5 mL
Difference in the water level = 35.5 - 25
= 10.5 mL
= 
We know that when a body is submerged in water, it displaces its own volume of water.
Therefore, the volume of the lead bar = volume of the water displaced = 10.5 mL =
We know that mathematically, density is the ratio of mass of body to its volume.
Density of the lead bar is given by :
=
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon).
Answer:
The grating spacing is 
Explanation:
From the question we are told that
The wavelength is 
The angle is 
The order of the spectrum is 
Generally in grating grating the condition for maxima to occur is
where d is the grating spacing
making d the subject of the formula
Substituting values
it is covalent because it does not dissolve in water
Energy is not required in passive transport,<span> and in active transport energy is required.
</span><span>In active transport, the molecules move against the concentration gradient that is from low to high concentration.
In passive transport, the molecules move with the concentration gradient thatis from high to low concentration.</span>
