The graph below shows the radioactive decay of a material.

The graph shows 'Time in billion years' on the x axis and 'Percent of original mass remaining' on y axis. On the x axis the points 0, 2, 4, 6, and 8 are marked. On the y axis points 25%, 50%, 75%, and 100% are marked. A smooth curve joins the points (0, 100%), (2, 25%), (4, 12.5%), (6, 6.25%), (8, 3.125%).

If the original mass of the radioactive material was 500 grams, after how many billion years will its mass become 125 grams?

2 billion years
4 billion years
6 billion years
8 billion years

Question

The graph below shows the radioactive decay of a material.

The graph shows 'Time in billion years' on the x axis and 'Percent of original mass remaining' on y axis. On the x axis the points 0, 2, 4, 6, and 8 are marked. On the y axis points 25%, 50%, 75%, and 100% are marked. A smooth curve joins the points (0, 100%), (2, 25%), (4, 12.5%), (6, 6.25%), (8, 3.125%).

If the original mass of the radioactive material was 500 grams, after how many billion years will its mass become 125 grams?

2 billion years
 4 billion years
 6 billion years
 8 billion years

ohyhyh · Answer

attachment

mhanifa · Answer

How many times the mass is decreased?

ohyhyh · Answer

@mhanifa wrote:

How many times the mass is decreased?

What do you mean?

mhanifa · Answer

The ratio of initial mass to the resultant mass

ohyhyh · Answer

@mhanifa wrote:

The ratio of initial mass to the resultant mass

Honestly, my teacher exempted a lesson and I believe it had to do with this. I don't know the terms. So IDK. It's important I get this question right though. I must get a good grade on this.

mhanifa · Answer

Can you determine the original mass of the radioactive material?

ohyhyh · Answer

@mhanifa wrote:

Can you determine the original mass of the radioactive material?

500? It says that in the question so I assume 500 which is also presented as %100 on the graph.

mhanifa · Answer

Good, and the target mass is ...

ohyhyh · Answer

@mhanifa wrote:

Good, and the target mass is ...

125

mhanifa · Answer

Excellent. If you divide 500 g by 125 g, you get ...

ohyhyh · Answer

@mhanifa wrote:

Excellent. If you divide 500 g by 125 g, you get ...

4?

mhanifa · Answer

Yes, 4 times means twice the half life

ohyhyh · Answer

@mhanifa wrote:

Yes, 4 times means twice the half life

so 2 billion?

mhanifa · Answer

2 billion would be one cycle of half life

ohyhyh · Answer

@mhanifa wrote:

Yes, 4 times means twice the half life

the graph says it reached 25% in 2 billion years and 125 is 25% so? thats my thought process

ohyhyh · Answer

or 4 billion

@mhanifa wrote:

2 billion would be one cycle of half life

mhanifa · Answer

You are right, it would be 2 billion years since its 25%

ohyhyh · Answer

ok. thank youuu

mhanifa · Answer

No problem, good luck!

ohyhyh · Answer

@mhanifa wrote:

No problem, good luck!

is there anyway you can help with this one too? The diagram below shows some ocean floor features. The diagram shows some ocean floor features. Feature A is the edge of a continent where the water is relatively shallow. Feature B is a sharp drop in depth where the ocean basin truly begins and the continental crust ends. Which of these statements best compares Feature A and Feature B? Feature A is the mid-ocean ridge and Feature B is the abyss. Feature B is the mid-ocean ridge and Feature A is the abyss. Feature B is the continental shelf and Feature A is the continental slope. Feature A is the continental shelf and Feature B is the continental slope.

ohyhyh · Answer

this is last one

mhanifa · Answer

I think you should add this as new question. Please also add the diagram

ohyhyh · Answer

@mhanifa wrote:

I think you should add this as new question. Please also add the diagram

okay hold on

1 attachment