Question

atomic theory (fill in the blanks) give name of scientist and name of model. 1. first atomic theory of matter: description of particles: first periodic table: 2. discovery of electrons: model name: 3. discovery of the nucleus: charge of the nucleus: model name: 4. discovery of electrons: model name: 5. discovery of orbitals: model name: (including neutrons, wave - like nature of electrons) 6. discovery of neutrons: 7. wave theory: quantum of energy: uncertainty principle: chlorine exists as two naturally occurring isotopes. cl - 35 occurs 75% of the time and cl - 37 occurs 25% of the time. which of the following calculations should be used to calculate the correct average atomic mass of chlorine? a (35 x 0.75)+(37 x 0.25) b (35 x 3)+37÷2 c (35 x 3)+37÷3 d (35 + 37)÷2

Explanation:

Step1: Recall average - atomic - mass formula

The formula for average atomic mass of an element with two isotopes is $A = m_1x_1 + m_2x_2$, where $m_1$ and $m_2$ are the masses of the isotopes and $x_1$ and $x_2$ are their fractional abundances.

Step2: Identify values for chlorine isotopes

For chlorine, $m_1 = 35$, $x_1=0.75$ (since Cl - 35 occurs 75% of the time), $m_2 = 37$, and $x_2 = 0.25$ (since Cl - 37 occurs 25% of the time).

Step3: Calculate average atomic mass

$A=(35\times0.75)+(37\times0.25)=26.25 + 9.25=35.5$

Answer:

The correct calculation to find the average atomic mass of chlorine is $(35\times0.75)+(37\times0.25)$.