Answer:

Explanation:
Data provided as per the question below:-
Wavelength = 430.nm
The computation of the frequency of the light is shown below:-
Frequency = Velocity of light ÷ Wavelength
The Velocity of light = 
Wavelength = 430 nm =
m
Frequency = 


= 
Therefore for determining the frequency we simply applied the above formula.
Answer:
There will 3.95 grams of Na2 and H2O that should be added to form a concentric required solution.
Answer: 4 molL-1
Explanation:
Detailed solution is shown in the image attached. The number of moles of NaCl is first obtained. Since the molarity must be in units of molL-1, the volume is divided by 1000 and the formula stated in the solution is applied and the answer is given to one significant figure.
Whenever the motion of an object changes . . . speeding up, or slowing down,
or changing direction . . . that change is called "acceleration". Acceleration is produced by force on the object.If there is no force on the object, then there is no acceleration. That means that
its motion doesn't change. The object remains in constant, uniform motion .
moving with steady speed, in a straight line.
No force is necessary to keep an object moving, only to change its motion.
Simple,
take a look at your periodic table, if you have it labeled look at the Halogen
Group, it includes: Flourine, Chlorine, Bromine, Iodine, and Astatine.
Now, a period on the periodic table is read from left to right, and goes
down the rows of the periodic table.
Go to Period 5, go all the way to the Halogens, what is there?
Iodine.
Thus, your answer.