Answer:
Classifying stars according to their spectrum is a very powerful way to begin to understand how they work. As we said last time, the spectral sequence O, B, A, F, G, K, M is a temperature sequence, with the hottest stars being of type O (surface temperatures 30,000-40,000 K), and the coolest stars being of type M (surface temperatures around 3,000 K). Because hot stars are blue, and cool stars are red, the temperature sequence is also a color sequence. It is sometimes helpful, though, to classify objects according to two different properties. Let's say we try to classify stars according to their apparent brightness, also. We could make a plot with color on one axis, and apparent brightness on the other axis, like this:
Explanation:
First of all, this is the chemistry section, while your question is a physics question. Anyway I'll tell you how to solve it.
First we need to find the rate that the truck moves in a second.
1km = 1000m
40km = 40000m
40000m/hr
1 hour = 60 minutes
40000m/hr ÷ 60 = 666.66(repeating)/minute
1 minute = 60 seconds
666.66m/min ÷ 60 = 11.11(rep)m/s
Next we simply multiply the speed of the truck by the number of seconds it travels.
11.11 × 5 = 55.55
Make sure to round it unless you indicate the repeating decimal.
The truck moved 55.56m in 5 seconds.
Answer: a) 
b) 1 mole of 
is produced.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The skeletal equation is:
The balanced equation will be:
Thus the coefficients are 2, 3 , 10 , 4 , 3 , 2 and 5.
b) Oxidation: 
Reduction: 
Net reaction: 
When 1 mole of 
is produced, 1 mole of is produced.
