Answer:
1. The energy intensity from the ruler going through the air
2. This one is pretty simple, you can add or take away things. This question is just asking you to list sounds from high pitch, to lowest pitch. Here are mine:
Timer
Microwave
Mouse clicking
Dog Barking
Voice
Typing
Knocking on door
Breathing
Foot Steps
Explanation:
Answer: 0.25 mol
Explanation:
Use the formula n=N/NA
n= number of mols
N = number of particles
Nᵃ = Avogadros constant = 6.02 x
So, n=
The 10 to the power of 23 cancels out and you are left with 1.505/6.02, which is approximately 1/4. This is the same as 0.25 mol.
Hope this helped :)
Answer:
NaCl will only conduct electricity in solutions
Explanation:
For electrical conduction, free mobile electrons as seen in most metals must be present or ions which are charged particles must be available for solutions and molten substances.
- Sodium chloride is an ionic compound without free mobile electrons or ions despite being ionic.
- It will maintain a subtle and unique charge stability when in solid form.
- In solid, the ions are not free to move and remain locked up in the solid mass.
- When introduced into a solution, the ions becomes free to move and this will aid electrical conduction.
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.
Ex: cutting a paper, gaining weight, cutting hair
Answer:
7 to 4 (higher 
)
5 to 3
3 to 2
4 to 2 (lower )
Explanation:
We can use the Rydberg formula which relates the wavelength of the photon emissions to the principle quantum numbers involved in the transition:
with 
final n, and 
initial n
evaluating for each transition:
7 to 4 
5 to 3 
4 to 2 
3 to 2 
Note that the above formula is written for 
, so lower value obtained involves higher .
So we should order from lower to higher
7 to 4 (higher )
5 to 3
3 to 2
4 to 2 (lower )
Note: Take into account that longer wavelength involves lower energy (
).
