Moles are used conveniently in chemistry especially in stoichiometric calculations involving reactions. The unit of mole is a collective term that holds 6.022×10^23 particles. These particles is a general term for any small units of matter including molecules, atoms and sub-particles. This ratio of 6.022×10^23 particles to 1 mole is known to be the Avogadro's number. Its exact number is actually <span>6.0221409</span>×10^23. We use this constant in our stoichiometric calculation as follows:
15 moles oxygen * (6.022×10^23 molecules/ 1 mole oxygen) = 9.033×10^24 molecules of oxygen
Answer:
The density of gallium would be greater than aluminium and boron.
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
As we move down the group densities increases because larger increase in mass occur with increase ion volume and greater sizes of elements down the group.
The boron, aluminium and gallium present in group thirteen. Boron is present in period two aluminium is present in period three and gallium is present in period four. So, atomic number of gallium is greater than boron and aluminium and it is appear as we move down the group. that's why gallium has larger size and greater value of density then boron and aluminium.
The value of density of gallium is 5.904 g/cm³.
That means that the amount of energy can only be certain numbers, as if
energy came in tiny packets, and the in-between amounts don't exist.
Another example of a measurement in nature that is quantized is
electric charge.
Answer:
C₄H₉O₂
Explanation:
just count the amount of atoms present in the model.
