Answer:
proposing a hypothesis.
Explanation: Therefore the last step in the scientific method is proposing a hypothesis or obtaining a conclusion.
Protons = 20
Electron = 20
Neutrons = 20
Hope this Helps :)
The molarity of KOH is 0.1055 M
<u><em> calculation</em></u>
Step 1: write the equation for reaction between H₂C₂O₄.2H₂O and KOH
H₂C₂O₄.2H₂O + 2 KOH → K₂C₂O₄ +4 H₂O
step 2: find the moles of H₂C₂O₄.2H₂O
moles = mass÷ molar mass
from periodic table the molar mass H₂C₂O₄.2H₂O= (1 x2) +(12 x2) +(16 x4) + 2(18)=126 g/mol
= 0.2000 g ÷ 126 g/mol =0.00159 moles
step 3: use the mole ratio to calculate the moles of KOH
H₂C₂O₄.2H₂O : KOH is 1:2
therefore the moles of KOH =0.00159 x 2 = 0.00318 moles
step 4: find molarity of KOH
molarity = moles/volume in liters
volume in liters = 30.12/1000=0.03012 L
molarity is therefore = 0.00318/0.03012 =0.1055 M
Answer:- Frequency is
.
Solution:- frequency and wavelength are inversely proportional to each other and the equation used is:

where,
is frequency, c is speed of light and
is the wavelength.
Speed of light is
.
We need to convert the wavelength from nm to m.
(
)

= 
Now, let's plug in the values in the equation to calculate the frequency:

=
or 
since, 
So, the frequency of the green light photon is
.