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2 years ago

Which of the following must be the same in atoms of the same element? (Ex: all atoms of silver)

Chemistry

1 answer:

rewona [7]2 years ago

4 0

Answer:

option b = atomic number

Explanation:

The atomic number of silver is 47. Its isotopes range from Ag⁹³ - Ag¹³² . The naturally occurring silver is made up of two stable isotopes i.e ₄₇Ag¹⁰⁷ and ₄₇Ag¹⁰⁹. The percentage of Ag¹⁰⁷ is 51.84% so it is more abundant than ₄₇Ag¹⁰⁹. Their atomic masses are different but the atomic number is same i.e 47.

A neutral atom have equal number of protons and neutrons. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example in case of silver 47 protons and 47 electrons are present. The number of protons or number of electrons are the atomic number of an atom while the number of protons and number of neutrons are the mass number of an atom. Every atom consist of nucleus or a positive center. The protons and neutrons are present with in the nucleus while electrons are present out side the nucleus. All these three subatomic particles construct an atom.

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A. 1

Lubov Fominskaja [6]

I think it’s B. I’m not 100% sure but I believe it is B! Srry if this is late btw.

8 0

2 years ago

Please answer as (a;3) < example>

never [62]

A;4, b;6, c;7, d;5, e;8, f;3

7 0

2 years ago

The heat of fusion AH, of ethyl acetate (C4H802) is 10.5 kinol. Calculate the change in entropy as when 398. g of ethy, acetate

Hitman42 [59]

Answer: The entropy change of the ethyl acetate is 133. J/K

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of ethyl acetate = 398 g

Molar mass of ethyl acetate = 88.11 g/mol

Putting values in above equation, we get:

$\text{Moles of ethyl acetate}=\frac{398g}{88.11g/mol}=4.52mol$

To calculate the entropy change for different phase at same temperature, we use the equation:

$\Delta S=n\times \frac{\Delta H_{fusion}}{T}$

where,

$\Delta S$ = Entropy change = ?

n = moles of ethyl acetate = 4.52 moles

$\Delta H_{fusion}$ = enthalpy of fusion = 10.5 kJ/mol = 10500 J/mol (Conversion factor: 1 kJ = 1000 J)

T = temperature of the system = $84.0^oC=[84+273]K=357K$

Putting values in above equation, we get:

$\Delta S=\frac{4.52mol\times 10500J/mol}{357K}\\\\\Delta S=132.9J/K$

Hence, the entropy change of the ethyl acetate is 133. J/K

7 0

2 years ago

8. __H2 + __O2-> __H2O

Rus_ich [418]

Anser:

Explanation:

hope this helps

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2 years ago

Systematic or Random Error? -This type of error affects overall accuracy but does not necessarily affect precision. This type of

love history [14]

Answer:

This type of error affects overall accuracy but does not necessarily affect precision. - Systematic error

This type of error affects precision but does not necessarily affect overall accuracy. - Random error

This type of error occurs if you use a buret that was calibrated incorrectly when it was made. - Systematic error

You can minimize this type of error by taking repeated measurements. - Random error

Explanation:

Systematic errors are errors that are attributable to instrument being used during measurement or consistent incorrect measurement during a research. They are consistently and repeatedly committed during measurements and therefore affect the overall accuracy of measurements. A person committing systematic error can have precise repeated measurement but will be far from being accurate.

Random errors on the other hand has no pattern and are usually unavoidable because they cannot be predicted. When sufficient replicate measurements are made, such errors are reduced to the barest minimum and usually do not affect the overall accuracy of measurements.

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2 years ago