Answer:
a. forces acting on the object
The answer is 42 grams of NaF are there in 1 mole.
<h3>
What is a mole ?</h3>
A mole is defined as 6.022 × 10²³ atoms, molecules, ions, or other chemical units.
and the molar mass of a substance is defined as the mass of 1 mole of that substance, expressed in grams per mole.
It is equal to the mass of 6.022 × 10²³ atoms, molecules, or formula units of that substance.
Molar Mass , i.e. mass of 1 mole of NaF is sum of molar mass of Na and F
23 + 19
42 grams
Therefore 42 grams of NaF Sodium-fluoride are there in 1 mole.
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Answer:
metalllll/material
Explanation:
you know how dark shirts absorb the sun heat well its practically the same just with material.
"Why is the inside of a car so hot after sitting in the sun?
Cars warm up in the sun due to the greenhouse effect: Sunlight passing through the windows into the car is mostly absorbed by interior surfaces, then radiated back to the air as heat. ... “As a consequence, the inside of the car will warm because radiation is coming in but not much is going back out.”Jul 27, 2009
Curiosities: Does a dark-colored car heat up more in the sun than a ..."
Answer:
Macroscopic observation
Explanation:
The observation is macroscopic because you could observe the transformation with the naked eye.
Answer:
0.9715 Fraction of Pu-239 will be remain after 1000 years.
Explanation:
Where:
= decay constant
=concentration left after time t
= Half life of the sample
Half life of Pu-239 = 
[
![\lambda =\frac{0.693}{24,000 y}=2.8875\times 10^{-5} y^{-1]](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B0.693%7D%7B24%2C000%20y%7D%3D2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D)
Let us say amount present of Pu-239 today = 
A = ?
![A=x\times e^{-2.8875\times 10^{-5} y^{-1]\times 1000 y}](https://tex.z-dn.net/?f=A%3Dx%5Ctimes%20e%5E%7B-2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D%5Ctimes%201000%20y%7D)
0.9715 Fraction of Pu-239 will be remain after 1000 years.
