If you look on the periodic table you will see the top group elements depending on how the elements relate to each in the column. All of the elements in that column show they all have 1 electron in their valence shell. Some of the chemicals in that family or group are Sodium, Lithium, Potassium. The are very reactive because they only have one electron and what 7 more to become stable.
An example of an aerobic activity would be A, Cross-country skiing
Answer: y = 2.4×10^-6m or y= 2.4μm
Explanation: The formulae for the distance between the central bright fringe to any other fringe in pattern is given as
y = R×mλ/d
Where y = distance between nth fringe and Central bright spot fringe.
m = position of fringe = 4
λ = wavelength of light= 600nm = 600×10^-9 m
d = distance between slits = 1.50×10^-5m
R = distance between slit and screen = 2m
y = 2 × 4 × 600×10^-9/2
y = 4800×10^-9/2
y = 2400 × 10^-9
y = 2.4×10^-6m or y= 2.4μm