Answer:
White being the color and coming in small grains.
Explanation:
Physical properties are something you can clearly see about the object.
Time taken for star to reach Earth = 7.5 years
<h3>Further explanation</h3>
Given
7.5 light years(distance Earth-star)
Required
Time taken
Solution
Speed of light=v = 3 x 10⁸ m/s
1 light years = 9.461 × 10¹⁵ m= distance(d)
So time taken for 1 light years :
time(t) = distance(d) : speed(v)
t = 9.461 × 10¹⁵ m : 3 x 10⁸ m/s
t = 3.154 x 10⁷ s = 1 years
So for 7.5 light years, time taken = 7.5 years
Answer:
The Avogadro's number is 
Explanation:
From the question we are told that
The edge length is 
The density of the metal is 
The molar mass of Ba is 
Generally the volume of a unit cell is
substituting value
![V = [5.02 *10^{-10}]^3](https://tex.z-dn.net/?f=V%20%3D%20%20%5B5.02%20%2A10%5E%7B-10%7D%5D%5E3)
From the question we are told that 68% of the unit cell is occupied by Ba atoms and that the structure is a metal which implies that the crystalline structure will be (BCC),
The volume of barium atom is
substituting value
The Molar mass of barium is mathematically represented as
Where 
is the Avogadro's number
So
substituting value
Answer:
your question is incomplete and its
particles which is one mole of a substance
Explanation:
you can solve the question by using this formular 1 mole of a substance=mass of the substance/ its molar mass
you find molar mass of a compound by adding individual molar masses of elements in that compound
Answer:
The student's conclusion is not correct
Explanation:
Activation energy is the minimum amount of energy required for a reaction to occur. All reactions require there activation energy to be met before the reaction can proceed. When the temperature of a reaction is increased, the kinetic energy of the reactant molecules increases; colliding more with each other, which makes them "surmount" the activation energy of the reaction faster as compared to a lower temperature.
In combustion, there is burning of an hydrocarbon (in this case propane) in excess oxygen. The burning assists in increasing the kinetic energy of the reactant particles which in turn easily surmounts the activation energy of the reaction by colliding (effective collision) more with oxygen. So, the reaction has an activation energy but the activation energy has been met and passed and hence the reaction is proceeding faster.
Increasing the temperature of a reaction is one of the ways of increasing the rate of a chemical reaction.
