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
fiasKO [112]
3 years ago
6

After three half-lives of an isotope 1 billion of those isotopes remain undecayed. How many atoms were in the original sample?

Chemistry
1 answer:
Ludmilka [50]3 years ago
5 0
I think its 8 billion
You might be interested in
What is the density of a liquid if it's volume is 125 mL and it's mass is 50g?
masha68 [24]

Answer:

0.4g/ml

Explanation:

density= mass/volume

density=50g/125ml

density=0.4g/ml

6 0
3 years ago
please help me with Chem I ONLY HAVE 5 MINUTES if methane gas (CH4) flows at a rate of 0.25L/s, how many grams of methane gas wi
Nookie1986 [14]

Answer:

643g of methane will there be in the room

Explanation:

To solve this question we must, as first, find the volume of methane after 1h = 3600s. With the volume we can find the moles of methane using PV = nRT -<em>Assuming STP-</em>. With the moles and the molar mass of methane (16g/mol) we can find the mass of methane gas after 1 hour as follows:

<em>Volume Methane:</em>

3600s * (0.25L / s) = 900L Methane

<em>Moles methane:</em>

PV = nRT; PV / RT = n

<em>Where P = 1atm at STP, V is volume = 900L; R is gas constant = 0.082atmL/molK; T is absolute temperature = 273.15K at sTP</em>

Replacing:

PV / RT = n

1atm*900L / 0.082atmL/molK*273.15 = n

n = 40.18mol methane

<em>Mass methane:</em>

40.18 moles * (16g/mol) =

<h3>643g of methane will there be in the room</h3>
5 0
3 years ago
2. An atom of Be has four protons, five neutrons and four electrons. What 10 poin
Goryan [66]

Answer:

Five ( 5 ) is the correct answer

7 0
3 years ago
How many grams of iron oxide, Fe2O3 will be produced if 165 g of O2 gas is supplied? (follow the same steps as mol to mol, only
forsale [732]

Answer:

m_{Fe_2O_3}=549gFe_2O_3

Explanation:

Hello there!

In this case, according to the given chemical reaction for this problem about stoichiometry:

4Fe+3O_2\rightarrow 2Fe_2O_3

Whereas there is a 3:2 mole ratio of oxygen (molar mass = 32.0 g/mol) to iron (III) oxide (molar mass = 159.69 g/mol) and therefore, the correct stoichiometric setup is:

m_{Fe_2O_3}=165gO_2*\frac{1molO_2}{32.00gO_2}*\frac{2molFe_2O_3}{3molO_2} *\frac{159.69gFe_2O_3}{1molFe_2O_3}  \\\\m_{Fe_2O_3}=549gFe_2O_3

Regards!

8 0
3 years ago
What type of element has 8 electrons in their outer most level?
RideAnS [48]

Answer:

Noble gases

Explanation:

Neon and argon have 8 electrons in their outermost shells. The elements which have 8 electrons in the outermost shell or in the valence shell,are known as the noble gases.

6 0
3 years ago
Read 2 more answers
Other questions:
  • Which of the following are true of phases?Check all that apply.A.The particles in a liquid are in a fixed location.B.Gases have
    13·1 answer
  • The most common form if matter in the universe is____?
    9·1 answer
  • Why does a planet stay in orbit?
    14·2 answers
  • Chemical weathering processes do not alter the chemical structure of minerals in rocks. *
    10·1 answer
  • HELP!! URGENT!! WILL GIVE BRAINIEST
    15·1 answer
  • Kidney stones are caused by the precipitation of either calcium oxalate, Ca(C2O4), or calcium phosphate, Ca3(PO4)2, in the kidne
    15·1 answer
  • If n=7 and l=6, What are the values of l?​
    11·1 answer
  • Yo why do females have to be so heartless to a guy who really put they all in for her?
    15·2 answers
  • A.Characterize each of the following as
    14·1 answer
  • I need four reasons why ph is important!!!
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!