All categories

3 years ago

How is the atomic mass of an element calculated from isotope data

Chemistry

1 answer:

Angelina_Jolie [31]3 years ago

8 0

Answer:

$aam=\frac{\Sigma m_{i} \times ab_{i} }{100}$

Explanation:

When an atom has 2 or more isotopes, the average atomic mass (aam) depends on the mass of each isotope (mi) and the percentual abundance in nature of each isotope (abi). The average atomic mass can be calculated using the following expression:

$aam=\frac{\Sigma m_{i} \times ab_{i} }{100}$

You might be interested in

What is the speed of a horse in meters per second that runs a distance of 1.2 miles in 2.4 minutes? (Hint: 1 mile = 1609 m)

dezoksy [38]

Time t=2.4 minutes=2.4×60=144 seconds
distance s=1.2 miles=1.2×1609=1930.8 meters
speed v=s/t=1930.8÷144=[tex] \frac{1930.8}{144} = \frac{160.9}{12} =[/13.408m/s ~nearly]

7 0

3 years ago

A particular laser consumes 130.0 Watts of electrical power and produces a stream of 2.67×1019 1017 nm photons per second.

solniwko [45]

The missing question is:

<em>What is the percent efficiency of the laser in converting electrical power to light?</em>

The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.

A particular laser consumes 130.0 Watt (P) of electrical power. The energy input (Ei) in 1 second (t) is:

$Ei = P \times t = 130.0 J/s \times 1 s = 130.0 J$

The laser produced photons with a wavelength (λ) of 1017 nm. We can calculate the energy (E) of each photon using the Planck-Einstein's relation.

$E = \frac{h \times c }{\lambda }$

where,

h: Planck's constant

c: speed of light

$E = \frac{h \times c }{\lambda } = \frac{6.63 \times 10^{-34}J.s \times 3.00 \times 10^{8} m/s }{1017 \times 10^{-9} m }= 6.52 \times 10^{-20} J$

The energy of 1 photon is 6.52 × 10⁻²⁰ J. The energy of 2.67 × 10¹⁹ photons (Energy output = Eo) is:

$\frac{6.52 \times 10^{-20} J}{photon} \times 2.67 \times 10^{19} photon = 1.74 J$

The percent efficiency of the laser is the ratio of the energy output to the energy input, times 100.

$Ef = \frac{Eo}{Ei} \times 100\% = \frac{1.74J}{130.0J} \times 100\% = 1.34\%$

The percent efficiency of the laser that consumes 130.0 Watt of electrical power and produces a stream of 2.67 × 10¹⁹ 1017 nm photons per second, is 1.34%.

You can learn more about lasers here: brainly.com/question/4869798

8 0

2 years ago

The escape of gas through a small hole in a container

Doss [256]

<span>The escape of gas through a small hole in a container is called effusion. This phenomenon happens when the diameter of the hole is small enough compared to the mean free path of the gas particles. This is governed by Graham's Law which states that the rate of effusion is inversely proportional to the molecular weight of the gas.</span>

7 0

3 years ago

When naming a compound made from a metal and a non-metal, what is done to the name of the second element?

RoseWind [281]

Metals combine with nonmetals to give ionic compounds. When naming binary ionic compounds, name the cation first (specifying the charge, if necessary), then the nonmetal anion (element stem + -ide). Hope this helps!

4 0

2 years ago

A sample of solid sodium hydroxide, weighing 13.20 grams is dissolved in deionized water to make a solution. What volume in mL o

Andreas93 [3]

<h3>Answer:</h3>

2.809 L of H₂SO₄

<h3>Explanation:</h3>

Concept tested: Moles and Molarity

In this case we are give;

Mass of solid sodium hydroxide as 13.20 g

Molarity of H₂SO₄ as 0.235 M

We are required to determine the volume of H₂SO₄ required

<h3>First: We need to write the balanced equation for the reaction.</h3>

The reaction between NaOH and H₂SO₄ is a neutralization reaction.
The balanced equation for the reaction is;

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

<h3>Second: We calculate the umber of moles of NaOH used </h3>

Number of moles = Mass ÷ Molar mass
Molar mass of NaOH is 40.0 g/mol

Therefore;

Moles of NaOH = 13.20 g ÷ 40.0 g/mol

= 0.33 moles

<h3>Third: Determine the number of moles of the acid, H₂SO₄</h3>

From the equation, 2 moles of NaOH reacts with 1 mole of H₂SO₄
Therefore, the mole ratio of NaOH: H₂SO₄ is 2 : 1.
Thus, Moles of H₂SO₄ = moles of NaOH × 2

= 0.33 moles × 2

= 0.66 moles of H₂SO₄

<h3>Fourth: Determine the Volume of the acid, H₂SO₄ used</h3>

When given the molarity of an acid and the number of moles we can calculate the volume of the acid.

That is; Volume = Number of moles ÷ Molarity

In this case;

Volume of the acid = 0.66 moles ÷ 0.235 M

= 2.809 L

Therefore, the volume of the acid required to neutralize the base,NaOH is 2.809 L.

7 0

3 years ago