Explanation:
one mole of any substance there are 6.022×1023 units of that substance. (This number is called Avogadro's number, NA.)
We need to convert the mass of silicon to moles using the molar mass of silicon, 28.06gmol. This number means that one mole of pure silicon would have a mass of 28.06g. Our given mass, however, is in milligrams; to convert this to grams we'll use the conversion factor 1g103mg:
5.86mg Si(1g103mg)=0.00586g Si
Now, using silicon's molar mass, we'll convert this mass to moles of Si:
0.00586g Si(1mol Si28.06g Si)=2.09×10−4mol Si
Finally, let's use Avogadro's number to convert
Answer:
The real answer for a is-He(helium)4,002602
The answer for b is-Mg(Magnesium) 24.305
Answer:
Explanation:
Given that:
From equation (3) , multiplying (-1) with equation (3) and interchanging reactant with the product side; we have:
Multiplying (2) with equation (4) ; we have:
From equation (1) ; multiplying (-1) with equation (1); we have:
From equation (2); multiplying (3) with equation (2); we have:
Now; Adding up equation (5), (6) & (7) ; we get:
<u> </u>
<u> </u>
<u />
(According to Hess Law)
Answer:
The correct answer is A.
Explanation:
The acids with hydrogen atoms in them are the ones that dissolve best in water and when they do, they get diluted, raising their pH level by releasing hydrogen ions (H+) into the solutions.
So when acids get dissolved in water, positively charged hydrogen atoms are released.
The answer is A.
I hope this helps.
Remember that the number of protons in the nucleus determines an element's identity. Chemical changes do not affect the nucleus, so chemical changes cannot change one type of atom into another. The number of protons in a nucleus does change sometimes, however. The identity of the atom, therefore, changes.
