Answer:
<h3>The answer is option B</h3>
Explanation:
To calculate the number of atoms we must first calculate the number of moles
Molar mass = mass / number of moles
number of moles = mass / Molar mass
Molar mass (K) = 39.10mole
mass = 2.10g
number of moles = 2.10/ 39.10
= 0.0537mol
After that we use the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10^23 entities
Number of K atoms is
N = 0.0537 × 6.02 × 10^13
<h3>N = 3.23×10^22 atoms of K</h3>
Hope this helps you.
During a phase change the temperature does not change since all of the heat is being absorbed in order to break the intermolecular forces. Due to that, the formula will not need to have T in it and is actually q=nΔH(v).
n=the number of moles (in this case 2.778mol of water since you divide 50g by 18g/mol).
ΔH(v)=the molar heat of vaporization (in this case 40.7kJ/mol).
q=the heat that must be absorbed
q=2.778mol×40.7kJ/mol
q=113.1kJ
Therefore the water needs to absorb 1.13×10²kJ.
I hope this helps. Let me know if anything is unclear.
It looks all correct to me, great job!
I believe the answer is gills
Fish's use gills to breathe, so tadpoles should use gills too
hope this helps
(got the info from a documentary i watched a couple years ago)
Pulmonary ventilation, and carbonic acid-bicarbonate buffering system
