All categories

2 years ago

If you have 10.0 g of a substance that decays with a half-life of 14 days, then how much will you have after 42 days?

1 answer:

6 0

The formula for the mass that remains:
$m=m_0 \times (\frac{1}{2})^\frac{t}{T}$
m₀ - the initial mass, t - time, T - the half-life

$m_0=10 \ g \\
T=14 \ d \\
t=42 \ d \\ \\
m=10 \times (\frac{1}{2})^\frac{42}{14}=10 \times (\frac{1}{2})^3=10 \times \frac{1}{8}=10 \times 0.125=1.25$

The answer is c. 1.25 g.

You might be interested in

Which of the following is best described as a synthesis reaction? (2 points) 2HgO → 2Hg + O2 AgNO3 + NaCl → AgCl + NaNO3 HCl + N

Shtirlitz [24]

2Na + Cl₂ → 2NaCl

Explanation:

The reaction of sodium metal with chlorine gas to produce sodium chloride is a typical example of synthesis reaction.

Combination or synthesis involves the formation of a single product from two or more reactants.

A + B ⇒ C

In this kind of chemical reaction, a single product is formed or some compounds by the union of elements is notable.

The driving force for this category of chemical reaction is the large and negative heat of formation of the product.

learn more:

Chemical reaction brainly.com/question/3953793

#learnwithBrainly

3 0

3 years ago

Read 2 more answers

Suppose that 2 scientists use different measurement systems in their work. What problems might arise if they shared their data?

bixtya [17]

<span>In assumption that there were two scientists who used different measurement systems in their research. The problems that might arise if they shared their data is obviously and primarily error. Errors are recognized and one element in every measure, system and quantity. Error was already even present in the measurement system alone a scientist used and it will furthermore aggregate, when these two different scales are combined the more error escalates in the process. There are two types: random and systematic error. </span>

8 0

3 years ago

Which atoms have the highest electronegativity?

Ronch [10]

Answer:

Note that there is little variation among the transition metals. Electronegativities generally decrease from top to bottom within a group due to the larger atomic size. Of the main group elements, fluorine has the highest electronegativity (EN = 4.0) and cesium the lowest (EN = 0.79).

3 0

2 years ago

The length of the minute hand of the clock is 14cm. Calculate the speed with which the tip of the minute hand moves

Molodets [167]

Speed of the tip of the minute hand=V=0.0244 cm/s

Explanation:

The angular velocity of the minute hand is given by

$\omega= \frac{2\pi}{T}$

T= time period of the minute hand=60 min=3600 s

so ω= 2 π/3600 rad/s

Now linear velocity v= r ω

r= radius of minute hand=14 cm

so v= 14 (2 π/3600)

V=0.0244 cm/s

8 0

2 years ago

ryan hypothesizes that darker colors heat up faster. he places a thermometer inside a red wool sock, a green cotton glove, and a

telo118 [61]

Light are transfer through waves in the atmosphere and yes it true that the darker the color is the more heat it could absorb thus it is also explain that the lighter the color is the less heat or light its absorb its because the light is bounces back through other form of light and it lessens the amount of heat in a substance. In Ryan's procedure the possible wrong that he done is the present of a green cotton glove. Green color are one of the color that bounces light and could not support the hypothesis of Ryan and the possible temperature he could get is not the accurate one.

3 0

3 years ago