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
Natalija [7]
3 years ago
14

An element has a half-life of 5.0 days. How many days would

Chemistry
1 answer:
Olin [163]3 years ago
3 0

Answer:

15 days

Explanation:

Given half-life = 5 days => k = 0.693/half-life = 0.693/5 days⁻¹

A = A₀e^-k·t => t = ln(A/A₀) / -k = ln(1/8) / -0.1386 days⁻¹ =  15 days

You might be interested in
How sig figs are in 28.0
Nadya [2.5K]
There are exactly (a). 10.0 and (b). 28.0
5 0
4 years ago
Read 2 more answers
 Convert the following to moles.
Luda [366]
Use dimensional analysis.
\frac{60.0 grams NaOH}{1} *  \frac{1 mole NaOH}{40.0 amu NaOH} =1.5 moles

\frac{2.73 grams NH4Cl}{1} *  \frac{1 mole NH4Cl}{53.49 amu NH4Cl} = .051 moles

Now you try converting moles to grams. All you have to do is start with MOLES  (Unlike the previous examples) over 1 then multiply that ratio by the ratio of molar mass over 1 mole. Hope this helps!
6 0
3 years ago
Which of the following salts will be less soluble in 0.10 M NaCl than it is in pure water?
MariettaO [177]

The less soluble salt : PbCl₂

<h3>Further explanation</h3>

Given

0.1 M NaCl

Required

The less soluble salt

Solution

If we see from the answer option, the salt that is more difficult to dissolve in NaCl is PbCl₂ because it has the same ion (Cl)

When PbCl₂ is dissolved in water, ionization will occur

PbCl₂ ⇒ Pb²⁺+ 2Cl⁻

So, when dissolved in NaCl, NaCl itself will be ionized

NaCl ⇒ Na⁺ + Cl⁻

Based on the principle of equilibrium, the addition of an ion (one of the ions is enlarged), the reaction will shift towards the ion that was not added. In addition to this Cl ion, the reaction will shift to the left so that the solubility of PbCl₂ will decrease (the reaction to the right decreases)

8 0
3 years ago
The elements in period 3 all have what characteric
Anastasy [175]
The answer is that they all have metallic structures
7 0
3 years ago
How many joules of heat are absorbed when 1000g of water is heated from 18Celsius to 85celsius?
o-na [289]

Answer + Explanations

Calculate heat absorption using the formula:

Q = mc∆T

Q means the heat absorbed, m is the mass of the substance absorbing heat, c is the specific heat capacity and ∆T is the change in temperature.

The heat absorbed is calculated by using the specific heat of water and the equation ΔH=cp×m×ΔT. 4. Water is vaporized to steam at 100oC. The heat absorbed is calculated by multiplying the moles of water by the molar heat of vaporization.

You can do this easily: just multiply the heat capacity of the substance you're heating by the mass of the substance and the change in temperature to find the heat absorbed.

To calculate the amount of heat released in a chemical reaction, use the equation Q = mc ΔT, where Q is the heat energy transferred (in joules), m is the mass of the liquid being heated (in kilograms), c is the specific heat capacity of the liquid (joule per kilogram degrees Celsius), and ΔT is the change in ...

Q = mc∆T. Q = heat energy (Joules, J) m = mass of a substance (kg) c = specific heat (units J/kg∙K) ∆ is a symbol meaning "the change in"

Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C. For comparison sake, it only takes 385 Joules of heat to raise 1 kilogram of copper 1°C.

A reaction that absorbs heat is endothermic. Its enthalpy will be positive, and it will cool down its surroundings. This reaction is exothermic (negative enthalpy, release of heat).

Quantitative experiments show that 4.18 Joules of heat energy are required to raise the temperature of 1g of water by 1°C. Thus, a liter (1000g) of water that increased from 24 to 25°C has absorbed 4.18 J/g°C x 1000g x 1°C or 4180 Joules of energy.

6 0
3 years ago
Other questions:
  • What is the compound of KCN called
    12·2 answers
  • When must scientist conduct controlled experiments ?
    13·1 answer
  • When the sentence best describes mass movement
    11·1 answer
  • Use the electronegativities in the periodic table above to determine which bonding pair forms polar covalent bonds.
    11·1 answer
  • What is the wavelength of light that has an energy of 8.0 x 109J​
    12·1 answer
  • Phagocytic cells perform their function by
    12·1 answer
  • Explain how the models you developed show that when methane combines with oxygen to form carbon dioxide and water, no atoms are
    8·1 answer
  • In a separate location, take notes from the sources you’ve identified. The notes will provide details for your paper. While taki
    14·1 answer
  • Which step you should take before performing a scientific investigation
    11·1 answer
  • What is the net ionic equation for this reaction?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!