<h3>The average atomic mass of Iodine : 126.86 amu</h3><h3>Further explanation</h3>
Given
80% 127I, 17% 126I, and 3% 128I.
Required
The average atomic mass
Solution
The elements in nature have several types of isotopes
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% + ... mass isotope n.%
Atomic mass of Iodine = 0.8 x 127 + 0.17 x 126 + 0.03 x 128
Atomic mass of Iodine = 101.6 + 21.42 + 3.84
Atomic mass of Iodine = 126.86 amu
<h2>Answer:</h2>
The correct answer is option C which is, "Electrons in the orbit closest to the nucleus have the least amount of energy".
<h3>
Explanation:</h3>
- There are different orbitals around the nucleus on which the electrons moves around the nucleus.
- These orbitals have a specific energy, due to which they are known as energy levels.
- The energy level near to the nucleus has least amount of the energy and the energy of the orbitals increase as the distance of the orbitals increase to the nucleus.
Answer
its a potassium elements
Explanation:
K 2,8,8,1 period num 4
group 1A
or 1s1 ,2s2 2p6, 3s1
its a metal reacted rapidly with water to form a colorless basic solution of potassium hydroxide (KOH) and hydrogen gas (H2). The reaction continues even when the solution becomes basic. The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic.
Answer:
88.8 minutes
Explanation:
Graham's law of diffusion relates rate of difusion by the following formula
Rate1 / rate 2 = √( Mass of argon / Mass of Neon)
Where rate = volume divided by time
Rate 1 = 10 ml / t1
Rate 2 = 10 ml / t2
Rate 1/ rate 2 = 10 ml / t1 ÷ 10 ml/ t2 = t2/ t1
t2/t1 = √(Mass of argon / mass of Neon) = √( 39.984/20.179)
125 / t1 = 1.4026
t1 = 125 / 1.4026 = 88.8 minutes
Answer:
2.65 M
Explanation:
Convert grams of K₂CO₃ to moles. The molar mass is 138.205 g/mol.
(110 g)/(138.205 g/mol) = 0.796 mol
Convert milliliters of solution to liters.
300 mL = 0.300 L
Divide moles of K₂CO₃ by liters of solution.
0.796 mol/0.300 L = 2.65 mol/L = 0.265 M
