Which of the following methods can be used to identify the suspected use of heat lamps in a house without entering the house?

A radioactive material has a count rate of 1600 counts per minute. It has a half life of 20 minutes. How long will it take to de

Natalka [10]

80 minutes because:

1600 -> 20mins -> 800

800 -> 20 mins -> 400

400 -> 20 mins -> 200

200 -> 20 mins -> 100

4*20 mins = 80 minutes

8 0

4 years ago

Describe the reasoning behind using phosphorus and boron in conjunction with one another.

Assoli18 [71]

defective greatest formerly knows sd ghost;

4 0

2 years ago

a radioisotope has a half life of three hours how much of a 120g sample remains after 9 hours. what will the g amount be after 3

aksik [14]

$\huge\boxed{♔︎Answer♔︎}$

60g after 3 hours, 30g after 6 hours and 15g after 9 hours

Explanation:

Weight of the radioactive sample = 120g

half life time period = 3 hours

(a) The weight of sample after 3 hours

$\textsf{ No. of half lives} = \sf \cancel\frac{3}{3} = 1$

The fraction of sample left

$\sf { \frac{1}{2} }^{1} = \frac{1}{2}$

Mass of the sample left

$\sf \frac{1}{2} \times 120 = \cancel\frac{120}{2} = 60g$

60g of sample is left after 3 hours

(b) The weight of sample after 6 hours

$\textsf{ No. of half lives} = \sf \cancel\frac{6}{3} = 2$

The fraction of the sample left

$\sf { \frac{1}{2} }^{2} = \frac{1}{2} \times \frac{1}{2} = \frac{1}{4}$

Mass of the sample left

$\sf \frac{1}{4} \times 120 = \cancel\frac{120}{4} = 30g$

30g of sample is left after 6 hours

(c) The weight of sample after 9 hours

$\textsf {No. of half lives} = \sf \cancel\frac{9}{3} = 3$

The fraction of sample left

$\sf { \frac{1}{2} }^{3} = \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8}$

Mass of sample left

$\sf \frac{1}{8} \times 120 = \cancel \frac{120}{8} = 15g$

15g of sample is left after 9 hours.

3 0

2 years ago

Select the correct answer from each drop-down menu. carbon is found in all living organisms. the constant flow of carbon on eart

Nady [450]

The continuous cycling of carbon in the earyh is known as the carbon cycle.

<h3>What is the carbon cycle?</h3>

The carbon cycle is a cycle which explains the various processes by which carbon is recycled between the atmosphere and the earth.

The constant flow of carbon on earth through organisms and the air is known as the carbon cycle. Plants absorb carbon from the atmosphere in the form of carbon dioxide. They use it for respiration and food production.

Animals consume plants, transferring carbon along the food chain.

Plants and animals respire and release carbon into air. When the animals and plants die, they are eaten by decomposers.

Carbon enters back into the atmosphere in the form of carbondio dioxide.

Therefore, the continuous cycling of carbon in the earth is known as the carbon cycle.

Learn more about carbon cycle at: brainly.com/question/25845923

#SPJ4

5 0

2 years ago

What are the chemical properties of iron meta

kari74 [83]

Answer:

Physical properties

Atomic mass: 55.845

Density: 7.87 g/cm3

Group: Transition metals

Electrons: [Ar] 3d6 4s2

Melting point: 1811 K

Boiling point: 3134 K

Discovered: Ancient times

Explanation:

hope this helps! :D

3 0

3 years ago