Answer: True!
Explanation: As electrons that are excited move between energy levels, they emit lots and lots of energy, in fact way more energy than ground state electrons (electrons that move within the same energy level) do, thus, making them more unstable.
Answer:
Kinetic energy
Explanation:
Objects or particles under motion posses energy in the form of kinetic energy which is directly proportional to the square of the velocity of the given particle.
E= 1/2mv² where m is the mass of the particle and v the velocity of the particle.
Answer:
Approximately 
.
Explanation:
Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.
<h3>Formula mass of strontium hydroxide</h3>
Look up the relative atomic mass of 
, 
, and 
on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.
Calculate the formula mass of 
:
.
<h3>Number of moles of strontium hydroxide in the solution</h3>
means that each mole of formula units have a mass of 
.
The question states that there are 
of in this solution.
How many moles of formula units would that be?
.
<h3>Molarity of this strontium hydroxide solution</h3>
There are 
of formula units in this 
solution. Convert the unit of volume to liter:
.
The molarity of a solution measures its molar concentration. For this solution:
.
(Rounded to four significant figures.)
Answer:
2
Explanation:
1. The dew is formed when the water vapor at the atmosphere contacts the leaves, which are at a low temperature, so, the vapor temperature decreases, and the liquid is formed. So, it's a gas to liquid change.
2. Ice cubes are at the solid-state, thus this transformation is solid to a liquid change.
3. The cold juice is at a low temperature, so when the water vapor of the air contacts with the glass, its temperature decreases, and its change to a liquid phase. So, it's a gas to liquid change.
4. The evaporated water from the Earth's surface goes to the atmosphere, and, at high altitudes, the temperature is low, so the water vapor condenses and the drops get closer together forming the clouds. So, it's a gas to a liquid change.
2. The coefficients represent to molar ratios in a balanced equation.
.
.
.