The answer would be C.
The salt and the water have both undergone physical changes.
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Answer:
Option B. +3 and +6
Explanation:
<em>Zeff</em> = <em>z - s</em>
where <em>z</em> is the atomic number, <em>s</em> is the number of shielding(non-valence) electrons
For Boron, electronic configuration is 1s²2s³.
z = 5, s = 2
Zeff = 5 - 2 = +3
For Oxygen, electronic configuration is 1s²2s²2p⁴
z = 8, s = 2
Zeff = 8 - 2 = +6
It will take 1.11 min to heat the sample to its melting point.
Melting point = - 20°C
Boiling point = 85°C
∆H of fusion = 180 J/g
∆H of vap = 500 J/g
C(solid) = 1.0 J/g °C
C(liquid) = 2.5 J/g °C
C(gas) = 0.5 J/g °C
Mass of sample = 25 g
Initial temperature = - 40°C
Final temperature = 100°C
Rate of heating = 450 J/min
Specific heat capacity formula:- q = m ×C×∆T
Here, q = heat energy
m = mass
C = specific heat
∆T = temperature change
Melting point = - 20°C
C(solid) = 1.0 J/g °C
∆T = final temperature - initial temperature = -20 - (-40) = 20
Put these value in Specific heat capacity formula
q = m ×C×∆T
q = 25×1.0×20
=500J
The Rate of heating = 450 J/min
i.e. 450J = 1min
so, 500J = 1.11min
1.11 minutes does it take to heat the sample to its melting point.
The specific heat capacity is defined as the amount of heat absorbed in line with unit mass of the material whilst its temperature increases 1 °C.
Learn more about specific heat capacity here:- brainly.com/question/26866234
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Answer:
The predominant intermolecular force in the liquid state of each of these compounds:
ammonia (NH3)
methane (CH4)
and nitrogen trifluoride (NF3)
Explanation:
The types of intermolecular forces:
1.Hydrogen bonding: It is a weak electrostatic force of attraction that exists between the hydrogen atom and a highly electronegative atom like N,O,F.
2.Dipole-dipole interactions: They exist between the oppositely charged dipoles in a polar covalent molecule.
3. London dispersion forces exist between all the atoms and molecules.
NH3 ammonia consists of intermolecular H-bonding.
Methane has London dispersion forces.
Because both carbon and hydrogen has almost similar electronegativity values.
NF3 has dipole-dipole interactions due to the electronegativity variations between nitrogen and fluorine.
The total charge on an atom comes from protons and electrons.
The proton is positively charged while the electron is negatively charged. A neutral atom would have an equal number of protons and electrons.
An atom with more protons than electrons will be positively charged while those with more electrons than protons will be negatively charged.
More on the atom can be found here: brainly.com/question/1641336
