<span>Electromagnetic radiation will be emitted when any
object has a temperature above zero. The
reason behind this is that atoms within any object at a temperature above
absolute zero have energy, and thus is moving.</span>
<span>Atoms are at least partly composed of charged
particles, changed particles must be moving too.</span>
Answer: There are
five <span>bonding pairs of electrons in Methanol.
Explanation: Those electron pairs which are being shared between two atoms in molecule are called as
bonding pair electrons. While, those electron pairs which are not involved in bond formation and are not shared between two atoms are called as
Non-Bonding electron pairs.
In molecule of
Methanol as shown below, it can be seen that carbon atom is forming four bonds with three hydrogen atoms and one oxygen atom by sharing four electron pairs and oxygen is forming two bonds, one with carbon atom and one with hydrogen atom. There are two lone pair of electrons present on oxygen atom which are not taking part in and formation.</span>
Answer : The mass of benzyl salicylate needed to manufacture 350 tubes of sunscreen are, 1.55 kg
Explanation :
As we are given that a sunscreen preparation contains 2.60 % by mass benzyl salicylate. That means, 2.60 grams of benzyl salicylate present in 100 g of solution.
First we have to convert the given mass from oz into kg.
Conversion used:
1 kg = 35.274 oz
or,

So,

Now we have to determine the mass of benzyl salicylate.
As, 100 g of solution contains mass of benzyl salicylate = 2.60 g
So, 0.1701 kg of solution contains mass of benzyl salicylate = 
Now we have to determine the mass of benzyl salicylate are needed to manufacture 350 tubes of sunscreen.
Mass of benzyl salicylate in 350 tubes of sunscreen = 0.00442 kg × 350
Mass of benzyl salicylate in 350 tubes of sunscreen = 1.55 kg
Thus, the mass of benzyl salicylate needed to manufacture 350 tubes of sunscreen are, 1.55 kg
Answer:
A) Concentration
Explanation:
When you add a chemical to itself it becomes more concentrated making it more powerful and faster
<u>Answer:</u> The percentage abundance of
isotope is 69 %.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
We are given:
Let the fractional abundance of
isotope be 'x'
- <u>For
isotope:</u>
Mass of
isotope = 62.93 amu
Fractional abundance of
isotope = x
- <u>For
isotope:</u>
Mass of
isotope = 64.93 amu
Fractional abundance of
isotope = (1-x)
- Average atomic mass of copper = 63.55 amu
Putting values in above equation, we get:
![63.55=[(62.93\times x)+(64.93\times (1-x))]\\\\x=0.69](https://tex.z-dn.net/?f=63.55%3D%5B%2862.93%5Ctimes%20x%29%2B%2864.93%5Ctimes%20%281-x%29%29%5D%5C%5C%5C%5Cx%3D0.69)
Converting this fractional abundance into percentage abundance by multiplying it by 100, we get:

Hence, the percentage abundance of
isotope is 69 %.