1.26 x 10²⁴particles
Explanation:
Given parameters:
Number of moles of the compound = 2.1 moles
Unknown:
Number of particles contained in the compound = ?
Solution:
A mole can be defined as the amount of a substance that contains Avogadro's number of particles 6.02 x 10²³.
The particles mentioned here can be atoms, molecules, formula units, ions, electrons, protons, neutrons and so forth.
To solve for the number of moles:
Number of particles = number of moles x 6.02 x 10²³
Number of particles = 2.1 x 6.02 x 10²³ = 12.64 x 10²³ = 1.26 x 10²⁴particles
Learn more:
mole calculation brainly.com/question/1841136
#learnwithBrainly
The correct option should be ultrasound technology (option B) because it is related to sonographers or ultrasound technicians. they are most likely with while pregnancy but they have plenty of uses, such as evaluating and diagnosis, many medical treatment for elderly patients.
1.04gK*1molK/39.01g K= 0.0267 mol K
0.70gCr*1mol/52.0g Cr = <span>0.0135 mol Cr
0.86 gO* 1 mol/16.0 g O = 0.0538 mol O
</span>0.0267 mol K/0.0135 = 2 mol K
0.0135 mol Cr /0.0135= 1 mol Cr
0.0538 mol O/0.035= 4 mol Cr
K2CrO4
Sodium-22 remain : 1.13 g
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
General formulas used in decay:

T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
half-life = t 1/2=2.6 years
T=15.6 years
No=72.5 g
