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3 years ago

13

If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?

1 answer:

Nonamiya [84]3 years ago

3 0

Answer:

3 half-lives

Explanation:

The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.

Let's suppose we start with 64 g of the radioactive element.

After 1 half-life, the mass of the element will be 32 g.

After 2 half-lives, the mass of the element will be 16 g.

After 3 half-lives, the mass of the element will be 8 g.

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How many moles of gas does it take to occupy 25.6 liters at a pressure of 6.2 atmospheres and a temperature of 309.3 K?

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Answer:

45 moles.

Explanation:

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2 years ago

Trava [24]

Answer: 2.52 M

Explanation:

The product of molarity (moles/litre) and volume in litres yields moles, and the numbers of moles in two solutions means dilute and concentrated are equal, which is expressed by the following equation:

$M_1V_1=M_2V_2$

$$Given that\\M $1=12.0 \mathrm{M}$ or mole $/ \mathrm{L}$\\$\mathrm{V} 1=420 \mathrm{ml}$\\$\mathrm{M} 2=$ ?\\$\mathrm{V} 2=2.0 \mathrm{~L}$ or $2000 \mathrm{ml}$\\\\$\mathrm{M} 1 \mathrm{~V} 1=\mathrm{M} 2 \mathrm{~V} 2$\\$\mathrm{M} 2=\mathrm{M} 1 \mathrm{~V} 1 / \mathrm{V} 2$\\$=12.0 * 420 / 2000$\\$=2.52 \ \mathrm{M}$

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2 years ago

The Bohr model of the Adam addressed the problem of

Sati [7]

It addressed the problem concerning why electrons didn't fall into the positive nucleus. HOPE THIS HELPS BRAINLIEST PLEASE

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3 years ago

A 25 kg rock is placed in a graduated cylinder with water.the volume of the fluid is 18.3ml.calculate the density of the rock in

ipn [44]

Answer:

=> 1366.120 g/mL.

Explanation:

To determine the formula to use in solving such a problem, you have to consider what you have been given.

We have;

mass (m) = 25 Kg

Volume (v) = 18.3 mL.

From our question, we are to determine the density (rho) of the rock.

The formula:

$p = \frac{m}{v}$

First let's convert 25 Kg to g;

1 Kg = 1000 g

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2 years ago

The volume (in L) that would be occupied by 5.00 mols of 02 at STP is

crimeas [40]

Answer : The volume of oxygen at STP is 112.0665 L

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Using ideal gas law equation :

$PV=nRT$

where,

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3 years ago