1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
alex41 [277]
4 years ago
12

A certain element consists of two stable isotopes. the first has a mass of 68.9 amu and a percent natural abundance of 60.4 %. t

he second has a mass of 70.9 amu and a percent natural abundance of 39.6 %. what is the atomic weight of the element?
Chemistry
1 answer:
Sauron [17]4 years ago
3 0
The average atomic weight of this element can be calculated as follows:
average atomic weight =
(atomic weight of first isotope)(its percentage of abundance) + 
(atomic weight of second isotope)(its percentage of abundance)

atomic weight of first isotope = 68.9 amu
its percentage of abundance = 0.604
atomic weight of second isotope = 70.9 amu
its percentage of abundance = 0.396

So, just substitute in the above equation to get the atomic weight of the element as follows:
atomic weight = (68.9)(0.604) + (70.9)(0.396) = 69.692 amu
You might be interested in
What do you use to find the actual amount of reactants
Rasek [7]

You need to use Stoichiometry

6 0
3 years ago
A gas is contained in a thick-walled balloon. When the pressure changes from 39.1 bar to 87.0 bar the volume changes from blank
lidiya [134]

Answer: -

1.34 L

Explanation: -

Initial Pressure P 1 = 39.1 bar

Initial Temperature T 1 = 643 K

Let the initial volume be V 1.

Final pressure P 2 = 87.0 bar

Final temperature T 2 = 525 K.

Final volume V 2 = 0.492 L

Using the equation

\frac{P1 V 1}{T1} = \frac{P 2 V 2}{T2}

V 1 = \frac{P2 V2 T1}{P 1 T2}

Plugging in the values

We have

V 1 = 87 bar x 0.492 L x 643 K / (39.1 bar x 525 K)

= 1.34 L

Thus, a gas is contained in a thick-walled balloon. When the pressure changes from 39.1 bar to 87.0 bar the volume changes from 1.34 L to 0.492L and the temperature changes from 643K to 525K

4 0
3 years ago
Read 2 more answers
What is the number density of magnesium?
lorasvet [3.4K]
1740 kg/m<span>3 is the density of magnesium

</span>
7 0
3 years ago
Calculate the amount of CO2 (in kg) released when 1 kg of coal is burned. Assume that carbon content of the coal is 50% by mass.
Delvig [45]

Answer:

1.8321 kg

Explanation:

The given 1 kg of coal contains 50% of the carbon atom by mass. Thus, mass of carbon in coal is \frac {50}{100}\times 1\ kg=0.5\ kg

Also, 1 kg = 1000 g

So, mass of carbon = 500 g

The formula for the calculation of moles is shown below:

moles = \frac{Mass\ taken}{Molar\ mass}

Molar mass of carbon = 12.0107 g/mol

Moles of methanol = 500 g / 12.0107 g/mol = 41.6295 moles

Considering the reaction:

C+O_2\rightarrow CO_2

From the reaction,

1 mole of C react to form 1 mole of CO_2

So,

41.6295 moles of C react to form 41.6295 moles of CO_2

Moles of CO_2 = 41.6295 moles

Molar mass of CO_2 = 44.01 g/mol

So, Mass = Moles × Molar mass = 41.6295 moles × 44.01 g/mol = 1832.1143 g

Also, 1g = 0.001 kg

<u>So, amount of CO_2 released = 1.8321 kg</u>

4 0
3 years ago
Ethanol is one of many toxic substances found in tobacco smoke. <br><br> a. True <br> b. False
maks197457 [2]

The statement is False.

Ethanol is one of many toxic substances found in tobacco smoke.

Ethanol is used in the manufacture of drugs, plastics, lacquers, polishes, plasticizers, and cosmetics. Ethanol is utilized in remedy as a topical antiinfective, and as an antidote for ethylene glycol or methanol overdose.

Ethanol is a natural chemical compound. it's far simple alcohol with the chemical formula C₂H₆O. Its system can be additionally written as CH ₃−CH ₂−OH or C ₂H ₅OH and is frequently abbreviated as EtOH. Ethanol is a risky, flammable, colorless liquid with a characteristic wine-like smell and pungent taste.

Within the worst instances, there can also be respiratory problems, low blood strain, incontinence coronary heart troubles, blood troubles, liver damage, and loss of life. Ethanol can also dry out and worsen the skin; there may be aches, redness, and swelling. Eye publicity to ethanol also can purpose tearing, burning, and stinging.

Learn more about Ethanol here brainly.com/question/842893

#SPJ4

5 0
2 years ago
Other questions:
  • Mr. Soto was trying to explain how electrons move around the nucleus of an atom in circular orbits. Which analogy BEST represent
    6·2 answers
  • How many liters of hydrogen gas will be produced at STP from the reaction of 7.179 x 1023 atoms of magnesium with 54.21 g of pho
    13·1 answer
  • Determine the molecular formula of a compound having the empirical formula C9H17O and a molar mass of 847.56g/mol.
    8·1 answer
  • An atom x contains 14 protons, 13 electrons, and 12 neutrons, and atom y contains 14 protons, 14 electrons, and 12 neutrons. wha
    8·2 answers
  • 12.7 grams of magnesium chloride is dissolved into water in a flask and set aside for an experiment. The scientist forgets about
    12·1 answer
  • A flask containing helium gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where
    7·1 answer
  • When 1 mole of hydrogen gas (H2) reacts with excess oxygen to form water at a constant pressure, 241.8 KJ of energy is released
    15·1 answer
  • Need help fast please 20 points
    14·2 answers
  • When an object accelerates, what about the motion changes
    13·1 answer
  • Short form of an element​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!