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3 years ago

Let this be an easy 5 points for your brainly account all is ask for in return is a "thank you"

Chemistry

1 answer:

Svet_ta [14]3 years ago

4 0

Answer:

The number of neutrons present in one atom of isotope of Silicon of mass 28 amu is 14 neutrons

Explanation:

Symbol of Si isotope

$_{14}^{28}\textrm{Si}$

Number of Neutron = Mass number - Atomic Number

Mass number = Total number of protons and neutrons present in the nucleus of the atom.For Si = 28 amu

Atomic Number = Total number of Protons present in the nucleus.

Si = 14

Number of neutron = 24 - 14

= 14

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What’s the distance from the nucleus of an atom to its theoretical outer edge of electron orbits

ollegr [7]

Answer:

The range of atoms = (30-300 pm) depending upon the element

Explanation:

The Atomic radii of the atom is the distance from the center of the circle to the outermost orbital.

The center of the circle is the nucleus and the radii is the outermost boundary.

The actual size of the atom is decided on the basis of the Zeff . Also known as effective nuclear charge.

Zeff: It is the net positive charge felt by the outermost electron by the nucleus.

The value of Zeff depends upon the shielding constant. More the shielding less will be the Zeff . Hence the size of the atom increases.

Due to shielding the outermost electrons feel less pull of nucleus.

The greater the Zeff , the smaller the radius of the atom.

The formula used to calculate the atomic mass is :

$r_{n}=\frac{52.9n^{2}}{Z}$ pm

Here "pm"= picometers

$1 pm = 10^{-12}m$

The size of the smallest atom H-atom = 120 pm

The range of atoms = (30-300 pm)

4 0

2 years ago

Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the following equation: CO2(s)→C

GREYUIT [131]

Answer:

$m=8.79kg$

Explanation:

First of all we need to calculate the heat that the water in the cooler is able to release:

$Q=\rho * V*Cp*\Delta T$

Where:

Cp is the mass heat capacity of water
V is the volume
$\rho$ is the density

$Q=1 g/cm^3 *15000 cm^3*4.184 \frac{J}{g*^{\circ}C}*(10-90)^{\circ}C$

$Q=-5020800 J=-5020.8 kJ$

To calculate the mass of CO2 that sublimes:

$-Q=\Delta H_{sub}*m$

Knowing that the enthalpy of sublimation for the CO2 is: $\Delta H_{sub}=571 kJ/kg$

$5020.8 kJ=571 kJ/kg*m$

$m=\frac{5020.8 kJ}{571 kJ/kg}=8.79kg$

6 0

2 years ago

Formation of water: 2H2 + 1 O2 --> 2H2O

noname [10]

Answer:

2.2 moles H2O

Explanation:

$35g O_2 \mbox{ \cdot }\frac{1mol}{32g/mol} \mbox{ \cdot }\frac{2mol H_2O}{1mol O_2}= 2.1875$ , which rounds to about 2.2

7 0

1 year ago

One mole of ANY element contains the:

VMariaS [17]

Answer:

1)The molar mass of an atom is simply the mass of one mole of identical atoms. However, most of the chemical elements are found on earth not as one isotope but as a mixture of isotopes, so the atoms of one element do not all have the same mass.

2)Equally important is the fact that one mole of a substance has a mass in grams numerically equal to the formula weight of that substance. Thus, one mole of an element has a mass in grams equal to the atomic weight of that element and contains 6.02 X 1023 atoms of the element.

3 0

2 years ago

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If the mass of all the reactants in a chemical reaction is 100g, what will the mass of all products be?

Delicious77 [7]

HUNDRED GRAMS too because of the law of conservation of mass. The law of conservation of mass states that mass is neither created nor destroyed. So both sides will have the same mass

6 0

3 years ago