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
nataly862011 [7]
3 years ago
8

A 320.9 ng sample of an unknown radioactive substance was placed in storage and its mass measured periodically. After 47 days th

e amount of radioactive substance had decreased to 40.11 ng. How many half‑lives of the unknown radioactive substance have occurred?
Physics
1 answer:
Aleks [24]3 years ago
5 0

Answer:

3 half life of the unknown radioactive substance have occurred.

Explanation:

Mass of sample = 320.9 ng

Mass after 1 half life = 0.5 x 320.9 = 160.45 ng

Mass after 2 half life = 0.5 x 160.45 = 80.225 ng

Mass after 3 half life = 0.5 x 80.225 =40.11 ng

So 3 half life of the unknown radioactive substance have occurred.

You might be interested in
Atoms with electronegativity differences below 0.4 generally form covalent<br>bonds. True or False​
STALIN [3.7K]

Answer:

True

Explanation:

Electronegativity difference of less than 0.4 characterized covalent bonds. For two atoms with an electronegativity difference of between 0.4 and 2.0, a polar covalent bond is formed-one that is neither ionic nor totally covalent.

7 0
3 years ago
Read 2 more answers
What are two ways you can increase power by climbing the stairs?
Nina [5.8K]

Answer:

change the

  • time
  • distance
  • force.

Explanation:

P = W/time

W = F*d

You have control over how fast you go up the stairs.

You also have control over how far up the stairs you go.

Therefore the answer is

  • time
  • distance

If you don't like distance as an answer, you can carry something up the stairs -- anything that increases F will do.

8 0
3 years ago
Determine the mass of Ar in 1.00 liter of a gas mixture at 25oC which contains 0.300 atm of Ne and has a total pressure of 4.00
sergejj [24]

Answer:

The mass of Ar is 36.91g

Explanation:

The gas mixture consist of Neon(Ne) and Argon(Ar)

Partial pressure of Ar = total pressure of mixture - partial pressure = 4 - 0.3 = 3.7 atm

Mole fraction of Ar = partial pressure of Ar ÷ total pressure of mixture = 3.7/4 = 0.925

Mass of Ar = 0.925 × molecular weight of Ar = 0.925 × 39.9 = 36.91g

4 0
3 years ago
Why do deer depend on plants to survive
jarptica [38.1K]
Deer depend on plants to survive because they are herbivores. Herbivores are animals that only eats plants and fruits in order to survive. Deer's meal includes grass and evergreen plants. If grass is unavailable, they eat whatever food like fallen leaves, twigs, bushes and other woody plants. 
5 0
4 years ago
A sound that's produced by a single wave at a constant frequency and with no overtones is called
notka56 [123]
It is called a pure sound
7 0
3 years ago
Other questions:
  • At high speeds, a particular automobile is capable of an acceleration of about 0.540 m/s^2. At this rate, how long (in seconds)
    8·1 answer
  • A red sphere of mass m and a blue sphere of mass 5m are attached to the ceiling by massless strings of identical length forming
    9·1 answer
  • The gas law for a fixed mass m of an ideal gas at absolute temperature T, pressure P, and volume V is PV=mRT, where R is the gas
    10·1 answer
  • Select a musical instrument. Research the instrument and explain how it works in terms of sound production and resonance. Descri
    8·2 answers
  • A student has an 80 g sample of a radioactive material that has a half-life of 20 seconds. How much material will he have left a
    5·1 answer
  • If a bag of pretzels says it contains 10 servings, and each serving is 150 calories, how many calories would you consume if you
    10·1 answer
  • Hey! please help i’ll give brainliest!
    12·1 answer
  • Question: A car (assumed to be a Ford Taurus) is traveling around a turn that is banked at 7 degrees. The turn has a radius of 2
    11·1 answer
  • Which factors would increase heating of Earth, and which factors would decrease it
    15·2 answers
  • Newton's 2nf law of motion States that
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!