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3 years ago

What do chemical changes and physical changes have in common

1 answer:

7 0

"Physical changes occur when objects or substances undergo a change that does notchange their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances."

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The energy diagram illustrated in the model corresponds to what student B

KatRina [158]

Answer: Exothermic reaction

Explanation:

Exothermic reactions lose energy, or ΔH, when they react.

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2 years ago

What was the name for the secret code used by many alchemists?

ahrayia [7]

Answer:

A. Zodiac

B. Palingenesis

C. Palabra mysteria

D. Decknamen

The correct answer is D. Decknamen.

Explanation:

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2 years ago

What is the relationship between atoms and static electricity

Mnenie [13.5K]

They both build up to form electricity

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2 years ago

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El ácido sulfúrico H2SO4 es uno de los compuestos que se utiliza para la producción de fertilizantes como el nitrosulfato amónic

Serjik [45]

Explanation:

12 hours ago

El ácido sulfúrico H2SO4 es uno de los compuestos que se utiliza para la producción de fertilizantes como el nitrosulfato amónico. Si disponemos de 8 mL de H2SO4 al 37 %P/P (d=1,26 g /mL), los cuales se disolvieron hasta alcanzar un volumen de solución de 400 mL, con una densidad de 1,08 g/mL. (La densidad del soluto es corresponde a 1,83 g/cm³)

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2 years ago

The two isotopes of chlorine are LaTeX: \begin{matrix}35\\17\end{matrix}Cl35 17 C l and LaTeX: \begin{matrix}37\\17\end{matrix}C

Kay [80]

Answer: The percentage abundance of $_{17}^{35}\textrm{Cl}$ and $_{17}^{37}\textrm{Cl}$ isotopes are 77.5% and 22.5% respectively.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

Let the fractional abundance of $_{17}^{35}\textrm{Cl}$ isotope be 'x'. So, fractional abundance of $_{17}^{37}\textrm{Cl}$ isotope will be '1 - x'

For $_{17}^{35}\textrm{Cl}$ isotope:

Mass of $_{17}^{35}\textrm{Cl}$ isotope = 35 amu

Fractional abundance of $_{17}^{35}\textrm{Cl}$ isotope = x

For $_{17}^{37}\textrm{Cl}$ isotope:

Mass of $_{17}^{37}\textrm{Cl}$ isotope = 37 amu

Fractional abundance of $_{17}^{37}\textrm{Cl}$ isotope = 1 - x

Average atomic mass of chlorine = 35.45 amu

Putting values in equation 1, we get:

$35.45=[(35\times x)+(37\times (1-x))]\\\\x=0.775$

Percentage abundance of $_{17}^{35}\textrm{Cl}$ isotope = $0.775\times 100=77.5\%$

Percentage abundance of $_{17}^{37}\textrm{Cl}$ isotope = $(1-0.775)=0.225\times 100=22.5\%$

Hence, the percentage abundance of $_{17}^{35}\textrm{Cl}$ and $_{17}^{37}\textrm{Cl}$ isotopes are 77.5% and 22.5% respectively.

6 0

2 years ago