Density multiplied by mass equal volume?

A chemist wishing to do an experiment requiring 47Ca2+(half-life = 4.536 days) needs 5.00 g of the nuclide. What mass of 47CaCO

Artyom0805 [142]

Answer: The answer is 6.78 grams.

Explanation: The equation used for solving this type of problems is:

$\frac{N}{N_0}=(\frac{1}{2})^n$

where, $N_0$ is the initial amount of radioactive substance, N is the remaining amount and n is the number of half lives.

Number of half lives is calculated on dividing the given time by the half life.

n = time/half life

Time is given as 48.0 hours and the half life is given as 4.536 days. let's make the units same and for this let's convert the half life from days to hours.

$4.536days(\frac{24hours}{1day})$

= 108.864 hours

So, $n=\frac{48.0}{108.864}$ = 0.441

Since 5.00 g is the required amount when the radioactive substance is delivered to the scientist, it would be the final amount that is N. We need to calculate the initial amount. Let's plug in the values in the equation:

$\frac{5.00}{N_0}=(\frac{1}{2})^0^.^4^4^1$

$\frac{5.00g}{N_0}=0.737$

$N_0=\frac{5.00g}{0.737}$

$N_0$ = 6.78 g

So, 6.78 g of the radioactive substance needs to be ordered.

4 0

4 years ago

if the piece of paper is cut in half over and over again, will there ever be a point at which it is no longer paper? explain you

Alisiya [41]

Answer:

No, cutting paper is a physical change. Meaning that it is still paper no matter how many times you cut it. its chemical properties have not changed and it is still paper. cutting it would just give you smaller pieces of paper.

4 0

4 years ago

Which of the following best represents potential energy being converted to kinetic energy? HELP

TiliK225 [7]

Answer:

B) A drawn bow is released, causing an arrow to fly across the field

Explanation:

Potential energy can be thought of as "potential" to do something. For eg, putting a ball on top of hill causes the ball to have the potential to roll down the hill if released. Here the ball converts the potential energy into kinetic energy (energy of motion) to roll down.

Similarly, the bow has been stretched (potential to fly if released), and when its released, it converts the potential energy into kinetic energy.

7 0

2 years ago

Whose atomic model could be described as a positive, solid sphere in which electrons are disbursed? A) Rutherford B) Dalton C) T

goldfiish [28.3K]

Thomson suggested the model of atom which was a sphere of positive matter within which electronic forces determined the positioning of the corpuscles. The corpuscles were distributed in a uniform sea of positive charge. This was so-called "plum pudding" model.
Answer: C ) Thomson

5 0

3 years ago

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An ideal gas described by Ti=291K, Pi=1.50bar, and Vi=13.3L is heated at constant volume until P=15.0bar. It then undergoes a re

Salsk061 [2.6K]

Answer:

$W=-4601.4J$