Radioactive isotope, also called radioisotope, radionuclide, or radioactive nuclide, any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays.
Answer:
Energy was transferred
Explanation:
If the temperature changed, energy must have been added or lost, but not created. Energy can't be created or destroyed.
Answer:
compound
Explanation:
MgO is an inorganic compund :) The simplest explanation is that it's not an element b/c there's two elements (Mg & O) in the substance, and it's not a mixture b/c you can't easily separate the two elements.
<span>HCN(aq)+SO4-2(aq)HSO4-(aq)+CN-(aq)
</span>
Bronsted-Lowry acid in this equation:<span>
Bronsted lowry acid=HCN(aq)
</span>Bronsted-Lowry Base in this equation:<span>
Bronstes lowry base =SO4-2
</span>Conjugate acid in this equation:
CA=CN-<span>
</span>Conjugate base in this equation
CB=HSO4- <span>
</span>
<h3>Answer:</h3>
a) Moles of Caffeine = 1.0 × 10⁻⁴ mol
b) Moles of Ethanol = 4.5 × 10⁻³ mol
<h3>Solution:</h3>
Data Given:
Mass of Caffeine = 20 mg = 0.02 g
M.Mass of Caffeine = 194.19 g.mol⁻¹
Molecules of Ethanol = 2.72 × 10²¹
Calculate Moles of Caffeine as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 0.02 g ÷ 194.19 g.mol⁻¹
Moles = 1.0 × 10⁻⁴ mol
Calculate Moles of Ethanol as,
As we know one mole of any substance contains 6.022 × 10²³ particles (atoms, ions, molecules or formula units). This number is also called as Avogadro's Number.
The relation between Moles, Number of Particles and Avogadro's Number is given as,
Number of Moles = Number of Molecules ÷ 6.022 × 10²³
Putting values,
Number of Moles = 2.72 × 10²¹ Molecules ÷ 6.022 × 10²³
Number of Moles = 4.5 × 10⁻³ Moles
