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
Alja [10]
3 years ago
11

The half-life of phosphorus-32 is 14.30 days. how many milligrams of a 20.00 mg sample of phosphorus-32 will remain after 85.80

days?
Chemistry
1 answer:
ZanzabumX [31]3 years ago
7 0
The amount of sample that is left after a certain period of time, given the half-life, h, can be calculated through the equation.

             A(t) = A(o) (1/2)^(t/d)

where t is the certain period of time. Substituting the known values,

             A(t) = (20 mg)(1/2)^(85.80/14.30)

Solving,

           A(t) = 0.3125 mg

Hence, the answer is 0.3125 mg. 
You might be interested in
BRAINLIEST IF CORRECT
Tpy6a [65]

Answer:

Explanation:

He should use these for airborne sounds

MDF Fiberboard.

Gypsum Board.

Plasterboard.

Mineral Wool.

He should avoid using

6 0
2 years ago
Which heats up the fastest? treated glass, aluminum, stainless steel, or copper?
GrogVix [38]

Answer:

stainless steel

Explanation:

stainless steel would heat up fast because it is made of metal

8 0
2 years ago
_________solution contains sodium hydroxide and copper sulphate​
Archy [21]
Biuret reagent. This is the answer
8 0
3 years ago
Read 2 more answers
An IV bag is labeled as 0.800% w/w sodium chloride in water solution with a density of 1.036g/mL. What is the concentration of s
Goryan [66]

Answer:

[NaCl] = 0.14 M

[NaCl] = 0.14 m

Mole fraction of NaCl → 2.48×10⁻³

Explanation:

This is a problem of concentration.

0.8% w/w means that in 100 g of solution, we have 0.8 g of solute, in this case NaCl.

Let's determine the volume with the density.

Solution density = Solution mass / Solution volume

1.036 g/mL = 100 g / Solution volume

Solution volume = 100 g / 1.036 g/mL → 96.5 mL

Let's calculate molarity (mol/L)

We convert the mass to moles (mass / molar mass)

0.8 g / 58.45 g/mol = 0.0137 moles

We must convert the volume of solution to L.

Molarity is mol/L, moles of solute in L of solution.

96.5 mL . 1L/1000 mL = 0.0965 L

0.0137 mol / 0.0965 L = 0.14 M

Let's determine molality and mole fraction.

Molality are moles of solute in 1 kg of solvent (mol/kg)

Mass of solution = Mass of solute + Mass of solvent

100 g = 0.8 g + Mass of solvent

100 g - 0.8 g = Mass of solvent → 99.2 g

Then, we must convert the mass of solvent to kg

99.2 g . 1kg / 1000 g = 0.0992 kg

Molality: 0.0137 mol / 0.0992 kg  → 0.14 m

Mole fraction → moles of solute / moles of solute + moles of solvent

Let's find out the moles of solvent ( mass / molar mass)

99.2g / 18 g/mol = 5.511 mol

Total moles = 5.511 + 0.0137 → 5.5247 moles

Mole fraction = 0.0137 / 5.5247 → 2.48×10⁻³

8 0
3 years ago
(I)how many atoms are present in 7g of lithium?
ICE Princess25 [194]

Answer :

(i) The number of atoms present in 7 g of lithium are, 6.07\times 10^{23}

(ii) The number of atoms present in 7 g of lithium are, 1.204\times 10^{24}

(iii) The number of moles of F_2 is, 1 mole

The number of moles of CO_2 is, 0.5 mole

The number of moles of OH^- is, 1 mole

Explanation :

<u>Part (i) :</u>

First we have to calculate the moles of lithium.

\text{Moles of }Li=\frac{\text{Mass of }Li}{\text{Molar mass of }Li}

Molar mass of Li = 6.94 g/mole

\text{Moles of }Li=\frac{7g}{6.94g/mol}=1.008mole

Now we have to calculate the number of atoms present.

As, 1 mole of lithium contains 6.022\times 10^{23} number of atoms

So, 1.008 mole of lithium contains 1.008\times 6.022\times 10^{23}=6.07\times 10^{23} number of atoms

Thus, the number of atoms present in 7 g of lithium are, 6.07\times 10^{23}

<u>Part (ii) :</u>

First we have to calculate the moles of carbon.

\text{Moles of }C=\frac{\text{Mass of }C}{\text{Molar mass of }C}

Molar mass of C = 12 g/mole

\text{Moles of }C=\frac{24g}{12g/mol}=2mole

Now we have to calculate the number of atoms present.

As, 1 mole of carbon contains 6.022\times 10^{23} number of atoms

So, 2 mole of carbon contains 2\times 6.022\times 10^{23}=1.204\times 10^{24} number of atoms

Thus, the number of atoms present in 7 g of lithium are, 1.204\times 10^{24}

<u>Part (iii) :</u>

<u>To calculate the moles of </u>F_2<u> :</u>

\text{Moles of }F_2=\frac{\text{Mass of }F_2}{\text{Molar mass of }F_2}

Molar mass of F_2 = 38 g/mole

\text{Moles of }F_2=\frac{19g}{19g/mol}=1mole

Thus, the number of moles of F_2 is, 1 mole

<u>To calculate the moles of </u>CO_2<u> :</u>

\text{Moles of }CO_2=\frac{\text{Mass of }CO_2}{\text{Molar mass of }CO_2}

Molar mass of CO_2 = 44 g/mole

\text{Moles of }CO_2=\frac{22g}{44g/mol}=0.5mole

Thus, the number of moles of CO_2 is, 0.5 mole

<u>To calculate the moles of </u>OH^-<u> ions :</u>

\text{Moles of }OH^-=\frac{\text{Mass of }OH^-}{\text{Molar mass of }OH^-}

Molar mass of OH^- = 17 g/mole

\text{Moles of }OH^-=\frac{17g}{17g/mol}=1mole

Thus, the number of moles of OH^- is, 1 mole

4 0
3 years ago
Other questions:
  • A mover packs books, CDs, and DVDs into a moving box. If the box contains 6.5 kg of books, 1.5 kg of CDs, and 2.0 kg of DVDs, wh
    8·2 answers
  • From left to right, the three regions of a phase diagram represent the _____ of a substance.
    13·2 answers
  • Which phrases accurately describe this rock? Check all that apply.
    10·1 answer
  • If element A has an ionic charge of +2 and element B has an ionic charge of -3, what will be the formula for the compound create
    7·1 answer
  • Two molecules of one reactant combine with 3 molecules of another to produce 5 molecules of a product.
    9·1 answer
  • Which of the following pair of elements could not react to form an ionic compound
    11·1 answer
  • Three examples of highly corrosive elements.
    5·1 answer
  • Write three primary alcohol with the formula C4H8O​
    13·1 answer
  • Please help me with 1,2,3,4,5,6 please I really need help
    12·1 answer
  • What are Ionic bonds?​
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!