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3 years ago

What is the total number of protons and neutrons in an atom called?

Chemistry

1 answer:

anzhelika [568]3 years ago

5 0

This is called the Mass Number of the isotope of the atom.

Isotopes are different forms of the same atom. They have the same number of protons but different number of neutrons.

Carbon-12 has mass number 12 as it has 6 protons and 6 neutrons.

Carbon-14 has mass number 14 as its has 6 protons and 8 neutrons.

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Please help me and thank you

Alex17521 [72]

Answer:

The physical and chemical properties of the product do not match the properties of the reactant.

Explanation:

Chemical change:

The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.

These changes are irreversible

These changes occur due to chemical reactions

These may not be observed with naked eye

Example:

Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood

Boiling of egg: that change the chemical composition of protein in the egg .

The reaction of Hydrogen and oxygen:

H 2 (g) + O 2 (g) -------------------------------------> 2H 2O (l)

The reaction between sugar and oxygen form a product which is different from the reactant that's why it indicate the occurrence of chemical reaction.

While in case of physical changes just state of matter are changed. Properties remain same.

6 0

2 years ago

U-238 has _____ protons and 146 neutrons

qaws [65]

U-238
The number besides the U means its total molar mass. The molar mass of this element is 238
Molar mass= protons + neutrons
This means that 238= 146 + protons
Do 238 - 146
Answer is 92

6 0

2 years ago

What are some of the positive and negative effects of the use of plastics?

trapecia [35]

Answer:

Positive: Save fuel and reduces greenhouse gas

Negative: Harmful to human and animal health ( underwater animals), Hurts the food chain

Explanation:

I got it from a video. Hopefully it helps you.

4 0

3 years ago

Magda has the two magnets shown below what will happen if magda tries to push the north poles of the two magnets toward one anot

ryzh [129]

They will repel one another because opposites attract, but like charges will repel.

8 0

3 years ago

CO2(g)+CCl4(g)⇌2COCl2(g) Calculate ΔG for this reaction at 25 ∘C under these conditions: PCO2PCCl4PCOCl2===0.140 atm0.185 atm0.7

padilas [110]

Answer: The $\Delta G$ for the reaction is 54.425 kJ/mol

Explanation:

For the given balanced chemical equation:

$CO_2(g)+CCl_4(g)\rightleftharpoons 2COCl_2(g)$

We are given:

$\Delta G^o_f_{CO_2}=-394.4kJ/mol\\\Delta G^o_f_{CCl_4}=-62.3kJ/mol\\\Delta G^o_f_{COCl_2}=-204.9kJ/mol$

To calculate $\Delta G^o_{rxn}$ for the reaction, we use the equation:

$\Delta G^o_{rxn}=\sum [n\times \Delta G_f(product)]-\sum [n\times \Delta G_f(reactant)]$

For the given equation:

$\Delta G^o_{rxn}=[(2\times \Delta G^o_f_{(COCl_2)})]-[(1\times \Delta G^o_f_{(CO_2)})+(1\times \Delta G^o_f_{(CCl_4)})]$

Putting values in above equation, we get:

$\Delta G^o_{rxn}=[(2\times (-204.9))-((1\times (-394.4))+(1\times (-62.3)))]\\\Delta G^o_{rxn}=46.9kJ=46900J$

Conversion factor used = 1 kJ = 1000 J

The expression of $K_p$ for the given reaction:

$K_p=\frac{(p_{COCl_2})^2}{p_{CO_2}\times p_{CCl_4}}$

We are given:

$p_{COCl_2}=0.735atm\\p_{CO_2}=0.140atm\\p_{CCl_4}=0.185atm$

Putting values in above equation, we get:

$K_p=\frac{(0.735)^2}{0.410\times 0.185}\\\\K_p=20.85$

To calculate the gibbs free energy of the reaction, we use the equation:

$\Delta G=\Delta G^o+RT\ln K_p$

where,

$\Delta G$ = Gibbs' free energy of the reaction = ?

$\Delta G^o$ = Standard gibbs' free energy change of the reaction = 46900 J

R = Gas constant = $8.314J/K mol$

T = Temperature = $25^oC=[25+273]K=298K$

$K_p$ = equilibrium constant in terms of partial pressure = 20.85

Putting values in above equation, we get:

$\Delta G=46900J+(8.314J/K.mol\times 298K\times \ln(20.85))\\\\\Delta G=54425.26J/mol=54.425kJ/mol$

Hence, the $\Delta G$ for the reaction is 54.425 kJ/mol

7 0

3 years ago