The following are scientific observations which led to development and changes of periodic table: Dmitri Mendeleev is the first periodic table organized 63 known element according to its properties, organized into rows and columns and inscribed name, mass and chemical properties on each element. Julius Lothar Meyer who independently worked in Germany with Ernest Rutherford. They experimented with 38 metals and found out that the positive charge of each element nucleus increased by one from element to element and organized the periodic table that tip to modern explanation of atomic number and the recognition of atomic number was the basis for organization of periodic table.
<u>Answer: </u>The amount of heat released is 84 calories.
<u>Explanation:
</u>
The equation used to calculate the amount of heat released or absorbed, we use the equation:
where,
Q = heat gained or released = ? Cal
m = mass of the substance = 10g
c = specific heat of aluminium = 0.21 Cal/g ° C
Putting values in above equation, we get:
Q = -84 Calories
Hence, the amount of heat released is 84 calories.
Answer:
Explanation:
Given parameters:
Initial temperature T₁ = 25.2°C = 25.2 + 273 = 298.2K
Initial pressure = P₁ = 0.6atm
Final temperature = 72.4°C = 72.4 + 273 = 345.4K
Unknown:
Final pressure = ?
Solution:
To solve this problem, we use an adaption of the combined gas law where the volume gas is fixed. This simplification results into:
where P and T are temperatures, 1 and 2 are initial and final temperatures.
Input the parameters and solve;
P₂ = 0.7atm
There are four atoms of fluorine present