Answer:
a) 965,1 lbf
b) 4,5 kg
c) 1,33 * 10^6 dynes
Explanation:
Mass of an object refers to the amount of mattter it cotains, it can be expressed it gr, kg, lbm, ton, etc.
Weight of an object refers to a force, and is the measurement of the pull of gravitiy on an object. It may be definide as the mass times the acceleration of gravity.
w=mg
In Planet Earth, the nominal "average" value for gravity is 9,8 m/s² (in the International System) or 32,17 ft/s² (in the FPS system).
To solve this problem we'll use the following conversion factors:
1 lbf = 1 lbm*ft/s²
1 N = 1 kg*m/s²
1 dyne = 1 gr*cm/s² and 1 N =10^5 dynes
1 ton = 907,18 kg
1 k = 1000 gr
a) m = 30 lbm

b) w = 44 N
First, we clear m of the weight equation and then we replace our data.

c) m = 15 ton
<span>Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles. We do as follows:
</span>10 mol NH3 ( 6.022 x 10^23 molecules / 1 mol ) = 6.022x10^24 molecules NH3
Answer:
Carbon - 13
Explanation:
For most of the elements other than that of hydrogen, the isotopes are named for the mass number.
Example : Carbon atoms with 6 neutrons have mass number of 12 ( as
), so they are known as carbon-12.
Given that:
Protons = 6
Neutrons = 7
Mass = 6 + 7 = 13
So the name is Carbon - 13 . The symbol is 
It would be 3C + 4H2 -> C3H8