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
Nikolay [14]
3 years ago
7

the half life of a certain element is 100 days. how many half-lives will it be before only one-fourth of this element reamains

Chemistry
1 answer:
Rama09 [41]3 years ago
4 0

Answer:

200 Days

Explanation:

Usually not so good in chemistry, but this is math!

Half life means in this time half goes away.  What happens when two half lives pass?  half of what was remaining goes away.  Maybe an example will make it more clear.

Say we start with 100 grams.  After the amount of time for the half life to pass completes, we have 50, or half of the original amount.  The half life time passes again and THAT gets cut in half to 25 grams.  this is 1/4 of the original (Hey, what we're looking for.)  Just to make it clear what is happening after another half life 1/8 remains, so it goes from The starting amount to 1/2 to 1/4 to 1/8 and so on, it keeps getting cut in half.

So how many times do we have to cut 1 in half until we get to 1/4?  Twice as was shown before.  Now, two half lives for this element is what?  100+100 days.  So 200 Days.

You might be interested in
Which solution is the best conductor of electric
nadezda [96]

(C) 0.1 mole of NaCl dissolved in 1,000. mL of water

<u>Explanation:</u>

The conductivity of 0.1 mole of NaCl dissolved in 1000 mL of water will be greatest as the number of ions in 0.1 mole of NaCl will be more than 0.001, 0.05 and 0.005 moles of NaCl. Greater the number of ions in the solution, greater will be the conductivity. Specific Conductivity decreases with a decrease in concentration. Since the number of ions per unit volume that carry current in a solution decrease on dilution. Hence, concentration and conductivity are directly proportional to each other.

4 0
3 years ago
Complete combustion of 7.50 g of a hydrocarbon produced 23.1 g of CO2 and 10.6 g of H2O. What is the empirical formula for the h
r-ruslan [8.4K]
A CH compound is combusted to produce CO2 and H2O 
CnHm + O2 -----> CO2 + H2O 
Mass of CO2 = 23.1g
 Mass of H2O = 10.6g
 Calculate by mass of the compounds
 For Carbon C, divide by molecular weight of CO2 and multiply with Carbon
molecular weight. So C in grams = 23.1 x (12.01 / 44.01) = 6.3 g C
 For Hydrogen H, divide by molecular weight of H2O and multiply with Hydrogen molecular weight. So H in grams = 10.6 x (2.01 / 18.01) = 0.53 g C
= 1.18 of H
 Calculate the moles for C and H
 6.3 grams of C x (1 mole/12.01 g C) = 0.524 moles of C
 1.18 grams of H x (1 mole/1.008 g H) = 1.17 moles of H
 Divides by both mole entities with smallest
 C = 0.524 / 0.524 = 1 x 4 = 4
 H = 1.17 / 0.524 = 2.23 x 4 = 10
 The empirical formula is C4H10.
7 0
3 years ago
Read 2 more answers
I need help with a questino
kipiarov [429]

Explanation:

What will the question be ?

6 0
3 years ago
Read 2 more answers
If a substance evaporates easily, it is said to be _______. volatile condensing crystallized changing pigmentation
Paraphin [41]
The correct answer is A.) Volatile. please mark brainliest (:
4 0
3 years ago
Read 2 more answers
A glucose solution that is prepared for a patient should have a concentration of 180 g/L. A nurse has 18 g of glucose. How
Irina-Kira [14]
<h3>Answer:</h3>

0.10 L

<h3>Explanation:</h3>

The concentration of glucose  is given as 180 g/L

The mass of glucose is 18 g

  • Concentration in g/L is calculated by dividing mass of the solute by the volume of the solution.
  • When calculating molarity on the other hand, we divide number of moles of the solute by the volume  of the solution.
  • Concentration in g/L = Mass of solute ÷ Volume

Rearranging the formula,

Volume = Mass of the solute ÷ concentration

             = 18 g ÷ 180 g/L

            = 0.10 L

Therefore, volume of water is 0.10 L

6 0
3 years ago
Other questions:
  • What is the difference between gamma radiation and x-ray radiation?
    5·2 answers
  • Which element will have the greatest attraction for the calcium electrons?
    13·1 answer
  • You have two 466.0 mL aqueous solutions. Solution A is a solution of silver nitrate, and solution B is a solution of potassium c
    9·1 answer
  • Under which conditions will sugar most likely dissolve fastest in a cup of water?
    6·1 answer
  • How many moles of aqueous sodium ions and sulfide are formed when 2.50 mil of sodium sulfide dissolved in water.
    7·1 answer
  • The emission spectrum for an element is? Select all that apply
    8·1 answer
  • How many atoms are there in 5K2CO3
    6·1 answer
  • Please help is for my final An example of a chemical change is-
    6·1 answer
  • A Bronsted-Lowry<br> _______is a molecule or ion that donates<br> a hydrogen ion in a reaction,
    6·1 answer
  • Remember that c is always about 300,000 km/s. Use the formula you identified to explain how the two factors in the formula are r
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!