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
svet-max [94.6K]
3 years ago
12

Question 6

Chemistry
1 answer:
hoa [83]3 years ago
8 0

Answer:

HELIUM IS HE ANSWER

Explanation:

<em>G</em><em>O</em><em>O</em><em>D</em><em> </em><em>LUCK</em>

You might be interested in
Promethium-147 is sometimes used in luminescent paint. It has a half-life of 956.3 days. If 250 grams (g) of promethium-147 is u
Fantom [35]

Answer:

% = 76.75%

Explanation:

To solve this problem, we just need to use the expressions of half life and it's relation with the concentration or mass of a compound. That expression is the following:

A = A₀ e^(-kt)   (1)

Where:

A and A₀: concentrations or mass of the compounds, (final and initial)

k: constant decay of the compound

t: given time

Now to get the value of k, we should use the following expression:

k = ln2 / t₁/₂   (2)

You should note that this expression is valid when the reaction is of order 1 or first order. In this kind of exercises, we can assume it's a first order because we are not using the isotope for a reaction.

Now, let's calculate k:

k = ln2 / 956.3

k = 7.25x10⁻⁴ d⁻¹

With this value, we just replace it in (1) to get the final mass of the isotope. The given time is 1 year or 365 days so:

A = 250 e^(-7.25x10⁻⁴ * 365)

A = 250 e^(-0.7675)

A = 191.87 g

However, the question is the percentage left after 1 year so:

% = (191.87 / 250) * 100

<h2>% = 76.75%</h2><h2>And this is the % of isotope after 1 year</h2>
3 0
2 years ago
Read 2 more answers
Which of the following shows the correct sequence of the Cell Cycle?
maria [59]
Interphase, prophase, metaphase, anaphase, telophase, cytokinesis is the right order!
5 0
2 years ago
Read 2 more answers
A. Identify the steps of the scientific method?
Greeley [361]

Answer:

1, experimentary

2, high potassium

3, testes

4, consistent

5, wi-fi

6, yes, it's not good enough

7, possibility

8, because it's not effective

Explanation:

thanks me later

6 0
2 years ago
Solve this questions please​
Andreyy89

Answer:

A

Explanation:

A solid that dissolves in water produce alkaline solutions

ex. sodium reacts with water to form sodium hydroxide – caustic soda

8 0
2 years ago
What type of temperature changes produce large crystals
vladimir1956 [14]
Warm temperatures will make crystals form quicker and larger
3 0
3 years ago
Other questions:
  • According to the Bohr model of an atom, what happens when an electron moves from the second energy level to the third energy lev
    13·2 answers
  • What is the molar mass of CaCl2?
    11·1 answer
  • Which of the following best describes electrolytes
    10·1 answer
  • The Valence Electrons of an Atom of Which Element would feel a Greater Effective Nuclear Charge than the Valence?
    13·1 answer
  • The effect of atoms colliding with the walls of a container is called ______.
    11·2 answers
  • Which statement is true? (2 points) Select one: a. Geothermal power plants use the renewable resource of heat from within the Ea
    14·1 answer
  • What is one use of the mineral gypsum?
    9·1 answer
  • A sample of an ideal gas has a mass of 0.311 grams. its volume is 0.225 l at a temperature of 55oc and a pressure of 1.166 atm.
    7·2 answers
  • Which of the following statements accurately describes the structure of the atom?
    12·1 answer
  • Which of the following is not conserved in a chemical reaction?
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!