Answer:
One
Explanation:
An element is a pure substance in which there are only one kind of atom. Elements are distinct substances that cannot be split up into simpler substances.
Such substances consists of only one kind of atom. There are over a hundred known elements to date.
Generally, as a pure substance, the composition of an element is definite and they are homogenous in all parts.
Metals are all in the center of the periodic table and are all made up of metals
Answer:
262.5 Joules
Explanation:
You find the kinetic energy of multiplying half of the mass by the velocity. In this word problem it tells you the mass so you divide it by 2. That answer is 2.625, you then multiply that by the velocity, in this instance it's 1.0 x 10^2 mi/h.
The unit in kinetic energy is Joules. This is actually a really important part in chemistry and physics.
D as it only has a negative effect when being used and it is small at that anyway.
Here we have to get the 
of the reaction at 520 K temperature.
The of the reaction is 1.705 atm
We know the relation between and 
is 
, where = The equilibrium constant of the reaction in terms of partial pressure, = The equilibrium constant of the reaction in terms of concentration and N = number of moles of gaseous products - Number of moles of gaseous reactants.
Now in this reaction, PCl₃ + Cl₂ ⇄ PCl₅
Thus number of moles of gaseous product is 1, and number of moles of gaseous reactants are 2. Thus N = |1 - 2| = 1 mole
The given value of is 4.0×10⁻²
The molar gas constant, R = 0.082 L. Atm. mol⁻¹. K⁻¹ and temperature, T = 520 K.
On plugging the values in the equation we get,
Or, = 1.705 atm
Thus, the of the reaction is 1.705 atm
