Answer:


Explanation:
d = Gap between slits = 0.142 mm
= Wavelength of light = 576 nm
L = Distance between light and screen = 3.5 m
m = Order = 2
Difference in path length is given by

The difference in path lengths is 
For dark fringe the difference in path length is given by

The difference in path length is 
centre of square disrance to each corner found by Pythagoras' theorem.
coulombs law used to clculate field of each charge at centre
fields added vectorially for res
Answer;
-Gases
Explanation;
-Pressure can affect the density of gases.
-Density of gases changes with pressure and temperature because gases are compressible fluid and because they are compressible, when pressure increases molecules come closer to each other which means increase in density and when pressure drops molecules of gases become free to expand and get away from each other which density decrease.
5.6 which would be acidic!
Answer:
1⁺ ion
Explanation:
Metals in the first group on the periodic table will prefer to form 1⁺ ion. This is because the 1 valence electron in their orbital.
Most metals are electropositive and would prefer to lose electrons than to gain it.
Like all metals, the group 1 elements called the alkali metals would prefer to lose and electron.
On losing an electron the number of protons is then greater than the number of electrons. This leaves a net positive charge.