Answer:
B. their outer electron levels are filled
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:
conductors
Explanation:
Because they consist of lattice of atoms with free electrons and these free electrons allows current to flow through.
Answer:
3.51× 10²³ formula units
Explanation:
Given data:
Mass of CaO = 32.7 g
Number of formula units = ?
Solution:
First of all we will calculate the number of moles.
Number of moles = mass/molar mass
Number of moles = 32.7 g/ 56.1 g/mol
Number of moles = 0.583 mol
Number of formula units:
1 mole = 6.022 × 10²³ formula units
0.583 mol × 6.022 × 10²³ formula units / 1 mol
3.51× 10²³ formula units
The number 6.022 × 10²³ is called Avogadro number.