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
sp2606 [1]
3 years ago
15

The half-life of radon-222 is 3.8 days. If a sample currently contains 3.1 grams of radon-222, how much radon-222 did this sampl

e have 15.2 days ago?
a 12.4 grams
b 47.1 grams
c 49.6 grams
d 57.8 grams
Chemistry
1 answer:
vodka [1.7K]3 years ago
5 0

The   number  of grams of  radon 222 did it have 15.2  ago was  49.6 grams( answer  C)

 <u>calculation</u>

  • calculate the number of half life it has covered    from   15.2  days to 3.8 days

             that is  divide 15.2/ 3.8 = 4 half life

  •  half  life is time taken for a radio activity  of a specified isotope to fall to half its original mass

therefore  3.8 days ago  it was  3.1 x2 =  6.2 grams

                  7.6 days ago  it was 6.2 x2 = 12.4 grams

                   11.4  days  ago it was 12.4  x2=  24.8  grams

                  15.2  days  ago  it was  24.8 x2=49.6 grams





You might be interested in
How were atomic models developed when no one had seen an atom?
AnnyKZ [126]
Atomic models were developed through indirect observation even though no one had seen an atom. There were many experiments of which I know nothing about, but in the end the scientists managed to come up with a formula and various models to describe atoms. 
4 0
3 years ago
Which term is the symbol for pressure? A. [A] B. k C. R D. x + y E. None of the Above
Elanso [62]
I believe the answer to your question is none of the above
5 0
2 years ago
Ba(NO3)2<br> What’s the atomic mass
Ahat [919]

Answer:

261.337 g/mol

Explanation:

3 0
3 years ago
Solve the quadratic equation 2x^2+13x=15 by method of completing the square<br>​
mafiozo [28]

Answer:

x = 1, -7.5

Explanation:

2x² + 13x = 15

Divide the left side of the equation by 2

2(x² + 6.5x) = 15

Divide 6.5 by 2 and square the quotient

6.5/2 = 3.25

3.25² = 10.5625

Add 10.5625 to the left side

2(x² + 6.5x + 10.5625) = 15

Since you have a 2 outside the parentheses, you will be adding 10.5625•2 to the right side.

10.5625 • 2 = 21.125

2(x² + 6.5x + 10.5625) = 36.125

To factor (x² + 6.5x + 10.5625), add b/2 to x

b/2 = 6.5/2 = 3.25

2(x + 3.25)² = 36.125

Divide by 2

(x + 3.25)² = 18.0625

Square root.

(x + 3.25) = √18.0625

x + 3.25 = ±4.25

Subtract 3.25.

x = 4.25 - 3.25 = 1

x = -4.25 - 3.25 = -7.5

x = 1, -7.5

4 0
3 years ago
a diatomic element has six bonding electrons, six non-bonding electrons, and 2 anti-bonding electrons. what is the bond order? g
Deffense [45]

The bond order of a diatomic element with  six bonding electrons, six non-bonding electrons, and 2 anti-bonding electrons is 2 whose formula is( bonding electrons-anti bonding electrons)/2.

<h3>What is an element?</h3>

An element  is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.

Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.

The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.

Learn more about element,here:

brainly.com/question/14347616

#SPJ2

7 0
1 year ago
Read 2 more answers
Other questions:
  • I WILL MARK BRAINLIEST
    12·1 answer
  • Draw the major organic product of the regioselective reaction of 2-methyl-2-pentene with H2O in presence of H2SO4. You do not ha
    8·1 answer
  • Suppose 870.mmol of electrons must be transported from one side of an electrochemical cell to another in 84. seconds. Calculate
    11·1 answer
  • Initially, scientists described atoms as the smallest particles of matter. However smaller particles within atoms were
    10·1 answer
  • What weight of sodium formate must be added to 4.00L of 1.00 M formic acid to produce a buffer solution that has a pH of 3.50?
    11·1 answer
  • Find the Ka of nitrous acid given that a 0.20 M solution of the acid has a hydrogen ion concentration of 2.8*10-3 M. HNO2 (aq) ?
    14·1 answer
  • The first five questions refer to the following problem:
    8·1 answer
  • How would one convert 125 lb to kilograms (1 oz = 28 g)?
    11·1 answer
  • What is the scientific notation of (41 e 23) (8.0 e 3)
    11·1 answer
  • Can anyone help me figure this out
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!