Answer:
18.1 g
Explanation:
You know that the atomic weight of phosphorus is equal to
30.794 u
, where
u
represent the unified atomic mass unit.
The unified atomic mass unit is equivalent to
1 g/mol
, but let's take the long road and prove that identity.
Now, the unified atomic mass unit is defined as
1
12
th
of the mass of a single unbound carbon-12 atom in its ground state and is equivalent to
1 u
=
1.660539
⋅
10
−
24
g
This means that the mass of one phosphorus atom will be
30.974
u
⋅
1.660539
⋅
10
−
24
g
1
u
=
5.14335
⋅
10
−
23
g
You know that one mole of any element contains exactly
6.022
⋅
10
23
atoms of that element - this is known as Avogadro's number.
Well, if you know the mass of one phosphorus atom, you can use Avogadro's nubmer to determine what the mass of one mole of phosphorus atoms
5.14335
⋅
10
−
23
g
atom
⋅
6.022
⋅
10
23
atoms
1 mole
=
30.974 g/mol
Finally, if one mole of phosphorus atoms has a mass of
30.974 g
, then
0.585
moles will have a mass of
0.585
moles
⋅
30.974 g
1
mole
=
18.1 g
From: https://socratic.org/questions/the-atomic-weight-of-phosphorus-is-30-974-u-what-is-the-mass-of-a-phosphorus-sam
The wavelength of the radiation is 4.7 x 10⁻⁹ m
What is the Einstein's Formula for Energy?
The energy
E is given, from Einstein's formula, as:
E=h⋅ν
Where:
h=6.63×10⁻³⁴Js is Planck's constant;
ν is the frequency.
You can relate frequency and wavelength
λ through the speed of light c as:
c=λ⋅ν
So finally you get:
E=hc/λ
It is given in the question
The energy of a photon is 4.23 x 10⁻¹⁷ J.
Wavelength = ?
λ = hc/E
λ = 6.63×10⁻³⁴x 3 x 10⁸ / 4.23 x 10⁻¹⁷
λ = 4.7 x 10⁻⁹ m
Therefore the wavelength of the radiation is 4.7 x 10⁻⁹ m .
To know more about Einstein's Equation for Energy
brainly.com/question/3505748
#SPJ1
The third one because temperature is being used, so a meter stick wouldn’t make sense. You aren’t measuring the length of anything physically. A stopwatch measures time, which is what they are showing in the chart, so the third one is the only one that makes sense.
Answer:
2.174 gm
Explanation:
PV = nRT n = number of moles
R = gas constant = .082057 L-atm/(K-mol)
T must be in units of K
.870 (3.95) = n (.082057)(35+273.15)
solve for n = .1359 moles
Methane mole weight (CH4) = 16 gm / mole
.1359 moles * 16 gm/mole = 2.174 gm
