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
DerKrebs [107]
2 years ago
14

the half life for strontium-90 is 29 years. how many half-lives did the sample go through at the end of 87 year​

Chemistry
2 answers:
tatuchka [14]2 years ago
6 0

= 87 : 29

= 3 half lives

Nesterboy [21]2 years ago
4 0
90 divided by 29 x 87 = 290
You might be interested in
Sydney and Valparaiso are the same distance from the equator and both are near the ocean. Is Valparaiso warmer, colder, or the s
PilotLPTM [1.2K]

Answer: It's colder.

Explanation: Well for starters Valparaiso is further away from the equator, and Australia is already really hot. But say that Valparaiso is further from the equator should be good enough.

5 0
3 years ago
Read 2 more answers
Which two practices are examples of how people use sciense
Semenov [28]

Answer: A: Explaining natural events using facts and data AND B:Developing theories using many lines of evidence

Explanation: trust me.

6 0
2 years ago
If the vapor's volume were to be incorrectly recorded as 125ml, how will this error affect the calculated molar mass of the unkn
pishuonlain [190]
Since you didn't give the actual volume (or any of the experimental values) I can only tell you how to do it. Do the calculation using the real (determined) volume of the flask. Then, re-do the calculation with v = 125ml. Take the two values and calculate % error; m = measured vol; g = guessed vol. 

<span>[mW (m) - mW (g)]/mW (m) x 100% </span>

<span>(they want % error so, if it is negative, just get rid of the sign) </span>
3 0
3 years ago
Estimate the heat of neutralization of H3PO4 in kJ/mol given these data: Heat transferred = 2.5 x 102 J Moles of H3PO4 = 1.4 x 1
OlgaM077 [116]
Below are the steps to get the answers:

<span>1.) write out the balance equation 3NaOh+H3PO4->Na3PO4+3H2O
 
2.) You are given everything needed to calculate q=heat transfer=2.2*10^2, H3PO4 moles= 1.5*10^-3, NaOH moles=5.0*10^-3
 
3.) equation is deltaHneutraliztion=q/Moles of limiting reagent H3PO4 is limiting reagent because lowest moles, and is used up first
 
4.) Now plug in variables DeltaH=2.2*10^2(1.5*10^3)= 146.67kj/mole Notice we had to convert J to kj, </span>
7 0
3 years ago
The isomers butane and methyl propane have
madreJ [45]

Explanation:

“The isomers butane and methyl propane have the same molecular formula and different properties”, this is because structural isomers usually have different properties to their parent.

3 0
3 years ago
Other questions:
  • Determine the mole fraction of the solute if you have 3.4 grams KCl in 8.1 grams H2O
    7·2 answers
  • A graduated cylinder is filled with 54.32 cm3 of water. An irregular solid made of iron is carefully placed into the graduated c
    12·1 answer
  • PLEASE I NEED HELP NOW!!! I WILL GIVE 25 POINTS
    11·1 answer
  • Water could be made to boil lower than its normal boiling point of 100 degrees Celsius at 92 degrees Celsius by?
    11·1 answer
  • Classic c fires include what?
    10·1 answer
  • The molar mass of magnesium fluoride is?
    5·1 answer
  • What is the density of a substance with a mass of 15.0 g and a volume of 5.0 mL?
    14·1 answer
  • How many electrons are in an atom with the electron<br> configuration of 1s 2s 2p 3s!?
    15·1 answer
  • How many valence electrons does selenium have?
    5·1 answer
  • Flowers are vascular plants.
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!