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# Elizabeth

• ### Half-life, elapsed time, decay equation formula?

The problem is:

-Iodine-131 had a half-life of 8.0 days.

-it is an 0.80mg sample.

-How long will it take to decay to 0.10mg?

I can do the problem but I don't remember the format.

I'm thinking:

Elapsed time = half-life * (half-life/[initial sample - final sample])

but I can't really remember, so I'm probably wrong

• ### How to find number of atoms in a mole of an element?

Example: "How many atoms are there in a 2.50 mol of hydrogen? Show all your work."

• ### What does the Spanish word "mima" mean?

My Spanish class is doing a dialogue, and I'm not sure what it means it this sentence. I've googles it which told me it meant "to spoil, pamper" but it doesn't make sense in the sentence:

"Vivo en la mima calle, en el 266."

and my teacher pronounces it like "mees-mah"

• ### My period always comes at a really weird time?

Sorry it's an awkward question

So I got my period when I was 11 and I just turned 15

It's always been weird and never on time (at most 2 weeks, early or late) but I've learned to expect it because I get my worst pains a day or two before

The weirdest thing is it always come right before an event

The first time it came the morning of my friends bday party and sleepover, so I just didnt sleepover

It always comes on Christmas (most of the time stays till new year) and my birthday

It always comes before my high school model un competitions (we go all around the state)

It came for my 8th grade trip to DC (that was on the 3rd-5th of the month, and it came AGAIN for my birthday on the 15th)

all my school dances

Halloween

If theres nothing going on, it comes for sleepovers

And it always comes for vacations!

On one vacation we were supposed to go to a watermark but my parents put it off unill the last day, lo and behold guess what arrived

I used to think it was caused my excitement or stress or something, maybe my hormones did something different?

But then things like this started:

So my mom told me my brothers college graduation was June 19 (this was sometime in late may she told me) from memory my period came June 5. Then my mom said she made a mistake the graduation was June 9!

Another time my period came on a Thursday, and later that the model un president said we were offered spots at a last minute competition Sat & Sun

Stuff like this always seems to happen, like it knows whats going to happen before I do!

Luckily it doesn't usually come the day of, normally it comes a few days before

Is my period psychic or am I just crazy?

Thank you for answers (or even just reading) this really weird question!