Answer:
1) energy = 15.6 kWh, 2) total_cost = $ 2.03
Explanation:
1) The energy dissipated is the product of the power and the time of use In a month it was used t = 6.5 h and the power of the toaster is
P = 2400 W = 2,400 kW
energy = P t
energy = 2,400 6.5
energy = 15.6 kWh
using rounding to a decimal
energy = 15.6 kWh
2) The cost of energy is unit_cost = $ 0.13 / kWh
so the total cost
total_cost = energy unit_cost
total_cost = 15.6 0.13
total_cost = $ 2.028
rounding to two decimal places
total_cost = $ 2.03
Answer:
A). A few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.
Explanation:
Scientists decided to change the model of the atom when they discovered new evidence that showed 'few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.' On this ground, <u>Rutherford concluded that atom is mostly made up of empty space and thus, he proposed a nucleus model of atom in which the atom comprises of the tiny and positively charged nucleus is surrounded by electrons with a negative charge</u>. Thus, <u>option A</u> is the correct answer.
Answer:
1 cm⁻¹ =1.44K 1 ev = 1.16 10⁴ K
Explanation:
The relationship between temperature and thermal energy is
E = K T
The relationship of the speed of light
c =λ f = f / ν 1/λ= ν
The Planck equation is
E = h f
Let's start the transformations
c = f λ = f / ν
f = c ν
E = h f
E = h c ν
E = KT
h c ν = K T
T = h c ν / K =( h c / K) ν
Let's replace the constants
h = 6.63 10⁻³⁴ J s
c = 3 10⁸ m / s
K = 1.38 10⁻²³ J / K
v = 1 cm-1 (100 cm / 1 m) = 10² m-1
T = (6.63 10⁻³⁴ 3. 10⁸ / 1.38 10⁻²³) 1 10²
A = h c / K = 1,441 10⁻²
T = 1.44K
ν = 103 cm⁻¹ = 103 10² m
T = (6.63 10⁻³⁴ 3. 10⁸ / 1.38 10⁻²³) 103 10²
T = 148K
1 Rydberg = 1.097 10 7 m
As we saw at the beginning the λ=1 / v
T = (h c / K) 1 /λ
T = 1,441 10⁻² 1 / 1,097 10⁷
T = 1.3 10⁻⁹ K
E = 1Ev (1.6 10⁻¹⁹ J /1 eV) = 1.6 10⁻¹⁹ J
E = KT
T = E/K
T = 1.6 10⁻¹⁹ /1.38 10⁻²³
T = 1.16 10⁴ K
Answer: b. The combination is a mixture because the substances can be separated
Explanation: Based on the facts presented above, the combination of both both substances can be referred to as a mixture due to the following:
A mixture is obtained when two or more substances or materials are combined without a chemical reaction. This is observed when Jalen combined substance 1 and 2 with only one of the substances becoming visible after the combination.
The other reason is that, a mixture can be separated back into its original constituent, this is evident when the combination was filtered with only substance 2 going through the filter and substance 1 remaining in the filter
