Answer:

Explanation:
The Rydberg equation gives the wavelength λ for the transitions:

where
R= the Rydberg constant (1.0974 ×10⁷ m⁻¹) and

Data:

λ = 657 nm
Calculation:

Answer:
D 30
Explanation:
whenever there is a reaction, the amount of atoms don't change, because matter can't be created or destroyed. Add the carbon and oxygen atoms together
Its like weight but not. mass is the amount of matter in a substance.
Answer:
Absolute error 
% Error
5
Explanation:
The absolute error is the the difference in the measured value and the actual value of a quantity.
Here the actual value is
grams
The measured value is
grams
Absolute error

Percent error

Where AE stands for absolute error and AV stands for absolute value.

%
Answer:
0.429 M
Explanation:
To find the molarity, you need to (1) convert grams to moles (using the molar mass), then (2) convert mL to L, and then (3) calculate the molarity (using the molarity ratio).
(Step 1)
Molar Mass (NaCl): 22.990 g/mol + 35.453 g/mol
Molar Mass (NaCl): 58.443 g/mol
18.8 grams NaCl 1 mole
-------------------------- x ------------------------ = 0.322 moles NaCl
58.443 grams
(Step 2)
1,000 mL = L
750.0 mL 1 L
------------------ x ----------------- = 0.7500 L
1,000 mL
(Step 3)
Molarity (M) = moles / volume (L)
Molarity = 0.332 moles / 0.7500 L
Molarity = 0.429 M