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
omeli [17]
4 years ago
12

The radioactive isotope z has a half-life of 12 hours. after 2 days, the fraction of the original amount remaining is

Chemistry
1 answer:
nataly862011 [7]4 years ago
4 0
.5•.5•.5•.5=1/2•1/2•1/2•1/2=1/4•1/4=1/16
You might be interested in
How many kj of heat are needed to completely melt 32.3 g of h2o, given that the water is at its melting point? the heat of fusio
timurjin [86]

Answer: fourth option, 10.8 kJ


Explanation:


The <em>heat of fusion</em>, also named latent heat of fusion, is the amount of heat energy required to change the state of a substance from solid to liquid (at constant pressure).


The data of the <em>heat of fusions</em> of the substances are reported in tables and they can be shown either per mole or per gram of substance.


In this case we have that the<em> heat of fusion for water </em>is reported per mole: <em>6.02 kJ/mole</em>.


The formula to calculate <em>how many kJ of heat (total heat) are needed to completely melt 32.3 g of water, given that the water is at its melting point</em> is:

  • Heat = number of moles × heat of fusion

The calculations are:

  • number of moles = mass / molar mass

        number of moles = 32.3 g / 18.015 g/mol = 1.79 mol

       

  • Heat = 1.79 mol × 6.02 kJ / mol = 10.8 kJ ← answer
5 0
3 years ago
Read 2 more answers
A 5.20 mol sample of solid A was placed in a sealed 1.00 L container and allowed to decompose into gaseous B and C. The concentr
ELEN [110]

Answer:

2.60 moles of A remaining.

Explanation:

According to  Le Chatelier's principle, the equilibrium would shift if the volume, concentration, pressure, or temperature changes.

In this question, we were told that  the volume doubles, that implies that we would have to double the molarity of B/ C (since B=C.)

However, it is obvious and clear from the given equation of the reaction that  A is  solid in it's activity = 1. Hence, it is then ignored.

So doubling B would be 1.30 M × 2 = 2.60 M

i.e 2.60 M moles of A was consumed.

Now;  the number of moles of A remaining  is 5.20 - 2.60 = 2.60 moles of A remaining.

5 0
3 years ago
What is the density of the mineral sample in g/cm3?
Vlad1618 [11]
4 degrees Celsius I think
7 0
3 years ago
Half of the first 18 elements have an odd number of electrons, and half have an even number. Show why atoms of these elements ar
asambeis [7]

Answer:

Diamagnetism in atom occurs whenever two electrons in an orbital paired equalises with a total spin of 0.

Paramagnetism in atom occurs whenever at least one orbital of an atom has a net spin of electron. That is a paramagnetic electron is just an unpaired electron in the atom.

Here is a twist even if an atom have ten diamagnetic electrons, the presence of at least one paramagnetic electron, makes it to be considered as a paramagnetic atom.

Simply put paramagnetic elements are one that have unpaired electrons, whereas diamagnetic elements do have paired electron.

The atomic orbital and radius increases by gaining electron linearly so even electron numbered atoms are diamagnetic while the odd electron numbered atoms are paramagnetic.

Running through the first 18 elements one can observe that there is an alternative odd number of electrons and an even number proofing that that half of the first 18 elements shows paramagnetism and diamagnetism respectively.

Explanation:

3 0
3 years ago
That gas can be used in mixtures with nitrogen gas to ripen bananas just before they are put on the grocery shelf. This mixture
Sphinxa [80]

Answer:

C2H4

Explanation:

The image attached shows a detailed solution of the above problem. The empirical formula shows the ratio of the atoms of each element present.

5 0
3 years ago
Other questions:
  • If atoms really conformed to the plum pudding model of the atom, what would the results of rutherford’s experiment have been?
    7·2 answers
  • What substance can act as catalysts in the body?
    12·1 answer
  • What is the major ion in seawater?
    6·1 answer
  • Use the words to complete the sentences. use each word one time
    8·1 answer
  • How are atomic and molecular orbitals related?
    11·2 answers
  • Give answer with correct number of significant figure 600*180
    13·1 answer
  • Which statement is true about dissolving?
    9·1 answer
  • What would the formula of an ionic compound made of Aluminum and Oxygen be?
    15·1 answer
  • Which equation best represents the balanced net ionic equation for the reaction that occurs when aqueous solutions of lithium ph
    12·1 answer
  • An isotope of hydrogen commonly referred to as heavy water is​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!