Via half-life equation we have:

Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:

There is 6.25 grams left of Ra-229 after 12 minutes.
Answer:
necessary for the growth, development and repair of all body tissues. it's involved in many body functions, including formation of collagen, absorption of iron, the proper functioning of the immune system, wound healing, and the maintenance of cartilage, bones, and teeth.
Explanation:
Answer:
D. transparent.
Explanation:
A material that transmits nearly all the light in a ray because it offers little resistance to the light is <u>transparent.</u>
A transparent material allows light to pass through them with little or no resistance enabling them see-through. A material that transmits nearly all the light rays that pass through it because it offers little resistance to the light is TRANSPARENT. Examples of transparent materials are water, glass (flint and crown), air, and diamond.
Answer:


Explanation:
<u>Temperature Units Conversion
</u>
The conversion formula between Celsius and Fahrenheit temperature scales is well-known. But we'll use the provided data to derive the formula. Let's model the relationship between Fahrenheit (F) and Celsius (C) as a linear function like

Where m and b must be computed according to the pair of conditions given. The values for each temperature scale are (C,F)=(0,32) and (100,212). Replacing the first value

It means that

By using the second point

Solving for m

Simplifying

So, the conversion formula is

Which is the widely known formula for temperature conversion
Solving for C, we get the inverse relation

Answer:
asi que sobre todo lol siento soy mexican y agora no se Como escribir en ingles
Explanation:
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