The unit expressed in 660 nm of light represents the wavelength of light. If you want to determine the frequency, you use the speed of light to relate the two. The formula is:
c = λν
where
λ is the wavelength
ν is the frequency
c is the speed of light = 3×10⁸ m
Apply SI units:
(3×10⁸ m) = (660×10⁻⁹ m)(ν)
Solving for ν,
<em>ν = 4.55×10¹⁴ s⁻¹</em>
Answer:
.
Explanation:
Lithium is in the first column of the periodic table, so it will have 1 valence electron.
Bromine is in the seventh column of the periodic table, so it will have seven valence electrons.
They must combine in a way to reach 8.
When combining elements to form compounds, the "crisscross method" is used. Above Li would be a charge of +1, and above Br would be a charge of -1.
Cross the 1 from the top of Li to the bottom of Br, and so there is 1 Br.
Cross the 1 from the top of Br to the bottom of Li, and so there is 1 Li.
It is not written BrLi because chemists decided to order them the other way. Technically speaking, it isn't wrong, but the positive charge is normally put on the left and the negative charge is normally put on the right.
The combustion reaction of propane would be expressed as:
C3H8 + 5O2 = 3CO2 + 4H2O
To determine the mass of water that is produced from the given amount of propane, we use the mass of propane and the relation of the substances from the balanced reaction. We do as follows:
moles propane = 22 g C3H8 ( 1 mol / 44.1 g ) = 0.50 mol C3H8
moles H2O = 0.50 mol C3H8 ( 4 mol H2O / 1 mol C3H8) = 2 mol H2O
mass H2O = 2 mol H2O ( 18.02 g / 1 mol ) = 36.04 g H2O
Therefore, the mass of water that is produced from 22 grams of propane would be 36.04 g.
Answer:
% composition O = 19.9%
% composition Cu = 80.1%
Explanation:
Given data:
Total mass of compound = 3.12 g
Mass of copper = 2.50 g
Mass of oxygen = 3.12 - 2.50 = 0.62 g
% composition = ?
Solution:
Formula:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition Cu = (2.50 g / 3.12 g)×100
% composition Cu = 0.80 ×100
% composition Cu = 80.1%
For oxygen:
<em>% composition = ( mass of element/ total mass)×100</em>
% composition O = (0.62 g / 3.12 g)×100
% composition O = 0.199 ×100
% composition O = 19.9%
A. electron. The nucleus has protons and neutrons, quark is the particle which forms protons and neutrons.
