A metallic substance separates into different metals when heated to certain temperatures. This substance may be an

A specialist that study substance obtained by attained mining is called a what

galina1969 [7]

Answer:

Explanation:

Mining:

Mining is when certain substances are removed from the Earth, usually in large quantities. Mining can occur below the surface of the Earth via tunnels and caves. It can also occur at surface level through methods such as strip mining, which removes huge amounts of soil in the process

7 0

1 year ago

Light elements with an atomic number less than 20 generally have a neutron to proton ratio equal to

Natalija [7]

Atomic elements consist of a nucleus that contains protons and neutrons. Protons carry a positive charge whilst neutrons are electrically neutral. In light elements with an atomic number less than 20, the neutron to proton ratio is generally equal to 1:1. This changes for heavier elements since the Coulomb interaction between many protons gets stronger and demands more neutrons for the nucleus to remain stable.

6 0

3 years ago

Five kg of carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar, 280 K to 20 bar

kaheart [24]

This question is incomplete, the complete question is;

Five kg of carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar, 280 K to 20 bar, 520 K. If the carbon dioxide behaves as an ideal gas, determine the amount of entropy produced, in kJ/K. Assuming;

a) constant specific heats Cp = 0.939 kJ/Kg K

b) variable specific heats

Answer:

a) the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced is 0.69845 kJ/K

Explanation:

Given the data in the question;

5 kg of carbon dioxide (CO₂) gas undergoes a process in a well-insulated piston-cylinder assembly.

m = 5 kg

Molar mass M = 44.01 g/mol

P₁ = 2 bar, P₂ = 20

T₁ = 280 K, P₂ = 520 K

Since its insulated { q = 0 } ( kinetic and potential energy effects = 0 )

Now,

a) the amount of entropy produced, in kJ/K, Assuming constant specific heats with Cp = 0.939 kJ/Kg K

S $_{Generation$ = m × ((Cp × In( T₂/T₁) - R × In( P₂/p₁ ))

we substitute

S $_{Generation$ = 5 × (( 0.939 × In( 520/280) - 0.1889 × In( 20/2 ))

= 5 × ( 0.5812778 - 0.434958 )

= 5 × 0.1463198

= 0.731599 kJ/K

Therefore, the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced, in kJ/K, Assuming variable specific heats.

Now, from Table A-23: Ideal Gas Properties of Selected Gases;

T₁,T₂ : s₁⁰ = 211.376 kJ/kmol-K, s₂⁰ = 236.575 kJ/kmol-K

now, s₁ = s₁⁰ / M and s₂ = s₂⁰ / M

we substitute

s₁ = s₁⁰ / M = 211.376 / 44.01 = 4.8029 kJ/kg

s₂ = s₂⁰ / M = 236.575 / 44.01 = 5.37548 kJ/kg

S $_{Generation$ = m × (( s₂ - s₁ ) - R × In( p₂ / p₁ ))

we substitute

S $_{Generation$ = 5 × (( 5.37548 - 4.8029 ) - 0.1880 × In( 20 / 2 ))

= 5 × ( 0.57258 - 0.432885997 )

= 5 × 0.13969

= 0.69845 kJ/K

Therefore, the amount of entropy produced is 0.69845 kJ/K

5 0

2 years ago

Explain what makes a covalently bonded molecule polar. Use the molecules of CH4 and CH3F as examples in your explanation.

RideAnS [48]

Answer:

See explanation

Explanation:

The magnitude of electronegativity difference between atoms in a bond determines whether that bond will be polar or not.

If the electronegativity difference between atoms in a bond is about 1.7, the bond is ionic. If the electronegativity difference is greater than 0.4 and less than 1.7, the bond will have a polar covalent character. Lastly, if the electronegativity difference between the bond is less than or equal to 0.4, the covalent bond is non polar.

The electronegativity difference between carbon and hydrogen is about 0.4 which corresponds to a nonpolar covalent bond hence the molecule is nonpolar.

The electronegativity difference between carbon and fluorine is about 1.5 indicating a highly polar bond. This gives CH3F an overall dipole moment thereby making the molecule polar.

8 0

3 years ago

explain how to determine the number of atoms, cations, and anions in ionic compounds. use an example to explain.

Damm [24]

Answer:

use coefficients and subscripts to determine how many atoms are in a compound. If there is no subscript or coefficient, assume it is 1. If there is a coefficient, multiply it with the subscripts. For counting cations and anions, determine first which is the anion and cation (anion = nonmetal, cation = metal), then count the number of that ion.

Example:

NaCl

one atom of Na, one atom of Cl. Since Na is a metal, it is a cation. Cl is a nonmetal, so it is an anion.

2CaCl2

2 atoms of Ca, 4 atoms of Cl. There are 2 cations, since Na is a metal, and 4 anions since Cl is a nonmetal

8 0

2 years ago