All categories

2 years ago

Consider a 100-gram sample of radioactive cobalt-60.

Chemistry

1 answer:

svetlana [45]2 years ago

7 0

It will take 5.2 years to decay.

The half life of cobalt-60 is 5.2 years. The half life is the time taken for the mass of the substance to decrease by a half.

here, the amount of remaining substance is 50%,

so, $(\frac{1}{2} )^{n} = 0.5$

n. log (0.5) = log (0.5)

n = 1

So it would take 1 half lives to decay this much, which is 1 x 5.2 which is 5.2 years.

what do you mean by radioactive decay ?

The process through which an unstable atomic nucleus loses energy via radiation is known as radioactive decay, also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration. A material that has unstable nuclei is considered as radioactive.

Learn more about decay here:-

brainly.com/question/13853996

#SPJ1

You might be interested in

SOMEONE PLEASE HELP

Zinaida [17]

Answer:

6. 7870 kg/m³ (3 s.f.)

7. 33.4 g (3 s.f.)

8. 12600 kg/m³ (3 s.f.)

Explanation:

6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.

1 kg= 1000g

1m³= 1 ×10⁶ cm³

Mass of iron bar

= 64.2g

= 64.2 ÷1000 kg

= 0.0642 kg

Volume of iron bar

= 8.16 cm³

= 8.16 ÷ 10⁶

$= 8.16 \times 10^{ - 6} \: kg$

$\boxed{density = \frac{mass}{volume} }$

Density of iron bar

$= \frac{0.0642}{8.16 \times 10^{ - 6} }$

= 7870 kg/m³ (3 s.f.)

$\boxed{mass = density \: \times volume}$

Mass

= 1.16 ×28.8

= 33.408 g

= 33.4 g (3 s.f.)

8. Volume of brick

= 12 cm³

$= 12 \times 10^{ - 6} \: m^{3} \\ = 1.2 \times 10^{ - 5} \: m ^{3}$

Mass of brick

= 151 g

= 151 ÷ 1000 kg

= 0.151 kg

Density of brick

= mass ÷ volume

$= \frac{0.151} {1.25 \times 10^{ - 5} } \\ = 12600 \: kg/ {m}^{3}$

(3 s.f.)

6 0

3 years ago

Which plate, oceanic or continental, must be more dense?

musickatia [10]

Answer:

Oceanic & Continental Plates

The oceanic plate is denser and sinks due to its lower buoyancy. It's sucked into the asthenosphere and is melted deeper into the Earth, called a subduction zone. The continental plate is less dense and floats over the top of it since it is more buoyant

4 0

3 years ago

Round to 4 significant figures: 42,561

arsen [322]

6 is the fourth significant figures

if the number behind it is 5 or more then 5, you must add 1 to the number and ALL the number behind it will turn into 0

so that the answer is 42560

7 0

3 years ago

Which physical state of nitrogen has the highest entropy? (1 point) solid liquid gas vapor?

Tju [1.3M]

Answer is. gas has the highest entropy.
Entropy is the measure of the molecular disorder and it is system’s thermal energy per unit temperature that is unavailable for doing useful work.
Nitrogen molecules have weakest intermolecular bonds in gas phase and move fast and without order. In solid state movement is much more less.

3 0

3 years ago

. Round to the nearest whole number

laila [671]

Answer:

21091mg of aspirin the person need to consume

Explanation:

To solve this question we must find the mass of the person in kg. Knowing the lethal dose for aspirin is 400mg/kg of person, we can find the amount of aspirin that the person need to consume to get a lethal dose:

Mass person:

116lb * (1kg / 2.2lb) = 52.7kg

Lethal dose:

52.7kg * (400mg / kg) =

<h3>21091mg of aspirin the person need to consume</h3>

3 0

3 years ago