Answer:
-It is considered the modern atomic model.
-It describes the probable locations of the electrons
Explanation:
edge 2020
Answer:- 0.134 seconds
Solution:- The speed is given as
and the circumference is 24900 miles which is same as the distance light have to covered. It asks to calculate the time required to cover this distance by the light.
We need to do unit conversion from miles to meter as the speed is given in meter per second.
1 mile = 1609.34 meter
So, 
= 40072566 meters
Know that, 
It's rearranged to time as, 
Let's plug in the values in it:

= 0.134 seconds
So, the light would take 0.134 seconds to travel the mentioned speed. The answer without the unit is 0.134.
Answer:
ΔH of solution is expected to be close to zero.
Explanation:
When we mix two non polar organic liquids like hexane and heptane,the resulting mixture formed is an ideal solution.An ideal solution is formed when the force of attraction between the molecules of the two liquids is equal to the force of attraction between the molecules of the same type.
For instance if liquids A and B are mixed,
=
= 
Hence the condition before and after mixing remains unchanged.
Since enthalpy change is associated with inter molecular force of attraction the enthalpy change for ideal solution is zero.
More examples of ideal solutions are:
1. Ethanol and Methanol
2. Benzene and Toluene
3. Ethyl bromide and Ethyl iodide
Yes due to the radioactivity having nothing to do with the chemical equation given it will release radiation at a rate determined by it's half life.
The answer is 200 g.
If the molar mass of CaCl2 is 110.98 g/mol, this means there are 110.98 g in 1 L of 1 M solution.
Let's find how many g of CaCl2 are present in 0.720 M.
110.98 g : 1 M = x : 0.720 M
x = 110.98 g * 0.720 M : 1 M
x = 79.90 g
So there are 79.90 g in 0.720 M. In other words, in 1 L of 0.720 M solution there will be 79.90 g.
Now, we need to prepare ten beakers with 250 mL of solutions:
10 * 250 mL = 2500 mL = 2.5 L
79.90 g : 1 L = x : 2.5 L
x = 79.90 g * 2.5 L : 1 L
x = 199.75 g ≈ 200 g