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
WITCHER [35]
3 years ago
12

Charcoal (burned wood) that was used to make prehistoric drawings on cave walls in france was scraped off and analyzed. the resu

lts were 4 mg carbon-14 (parent isotope) and 60 mg nitrogen (daughter isotope). the half-life of carbon-14 is 5,730 years. how old are the cave drawings?
a. 11,460 years
b. 17,190 years
c. 22,920 years
d. the sample is too old to be analyzed by carbon dating.
Chemistry
1 answer:
Finger [1]3 years ago
6 0
TLDR: the answer is C. 22,920 years.

Half-life describes the amount of time for a radioactive substance to decay to one-half of the original substance’s weight. So, if we had 100g of C-14, after 5,730 years, only 50g remain; after another 5,730 years, only 25g would remain, and so on.

In this problem, we are meant to assume that the original amount of C-14 was 64g, and that, through decay, it forms N-14. We can figure out how many half lives have passed by figuring out how much 4 is out of 64 by dividing 64 by two repeatedly. Each time, count a half life.

64 - 32 (1 HL) - 16 (2 HL) - 8 (3 HL) - 4 (4 HL)

In this problem, 4 half lives have passed. We can now multiply this by the time for one half life to find how many years have passed.

4 x 5,730 = 22,920 years

Approximately 22,920 years have passed since the drawing was created.
You might be interested in
I need helpppp plzzzz
Inessa [10]

Answer:

at first i would like to tell which class

Explanation:

125000 is the answwr

8 0
3 years ago
The longest day, and shortest night, of the year occurs on the
BaLLatris [955]

Answer:

This is the first answer,

winter solstice

The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (usually December 21 or 22) and in the Southern Hemisphere, this is the June solstice (usually June 20 or 21).

and this is the second one,

the tilt of the Earth on its axis

Seasons change because of the tilt of the Earth and the planet's movement around the Sun. Did you know? It takes about 365.25 days for the Earth to orbit the Sun. We have leap years to make up for the extra ¼ day!

5 0
3 years ago
Which list ranks the gasses in the correct order from the
JulijaS [17]

Answer:

D. chlorine, oxygen, nitrogen, hydrogen.

Explanation:

  • Thomas Graham found that, at a constant  temperature and pressure the rates of effusion  of various gases are inversely proportional to  the square root of their masses.

<em>ν ∝ 1/√M</em>

where ν is the rate of effusion and M is the atomic  or molecular mass of the gas particles.

  • The molecular mass for the listed gases are:

O₂: 32.0 g/mol,

Cl₂: 70.906 g/mol,

N₂: 28.0 g/mol,

H₂: 2.0 g/mol.

  • Hence, the smallest molecular mass of the gas, the fastest rate of effusion.

So, the order from the slowest to the fastest rate of effusion is:

<em>Chlorine, oxygen, nitrogen, hydrogen.</em>

6 0
3 years ago
Read 2 more answers
Polar bears give birth and hunt on sea ice. Which of the following would help polar bears survive during the melting of Arctic i
galina1969 [7]

i think the answer is the second one

4 0
3 years ago
Read 2 more answers
How many liters of 4M solution can be made using 100 grams of lithium bromide
uysha [10]
Molar mass of LiBr (mm )= 86.845 g/mol

Molarity ( M ) = 4 M 

Mass of solute ( m ) = 100 g

Volume ( V ) = in liters ?

V = m / mm  * M

V = 100 / 86.845 * 4

V = 100 / 347.38

V = 0.2875 L

hope this helps!.
5 0
3 years ago
Other questions:
  • Mercury(II) oxide (HgO) decomposes to form mercury (Hg) and oxygen (O2). The balanced chemical equation is shown below. 2HgO mc0
    15·2 answers
  • Anne brought a 1 L bottle of vinegar from home to use in an experiment on volcanoes in science class. she poured the contents of
    5·1 answer
  • Which type of compound dissociates?
    13·1 answer
  • In Experiment 9, a 1.05 g sample of a mixture of NaCl (MW 58.45) and NaNO2 (MW 69.01) is reacted with excess sulfamic acid. The
    13·1 answer
  • Sulfuric acid is formed when sulfur dioxide reacts with oxygen and water. Write a balanced chemical equation for the reaction. (
    14·1 answer
  • The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with mean = 110 grams and standard deviation =
    5·1 answer
  • 9. Which of the following concentrations has units of moles of solute per liter of solution?
    12·1 answer
  • How can living things be classified? What are the criteria?
    5·2 answers
  • Make propanoic anhydride from Formaldehyde
    9·1 answer
  • Which feature of the state means absolute authority within the country?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!