Answer:
Cabon-12 has same average atomic weight and mass number.
Explanation:
carbon-12 has average atomic weight 12 amu and mass number of 12.
amu represents average of mass of a nucleon.
As carbon-12 has same average atomic mass and mass number therefore carbon-12 is a good standard to determine average mass of a nucleon.
Again, abundance of carbon-12 isotope is almost equal to 99%. Therefore fluctuation of average atomic weight from 12 amu is very very low.
So, carbon-12 is taken as a standard to determine mass of a nucleon.
Hence atomic mass of carbon-12 is 12 amu.
It's a chemical change because a new compound is formed
In the first situation: the mechanism of covection is the main form of heat transfer when warm air from a heater moves around and upward.
In the case of the metal pan the mechanism of heat transfer is conduction.
In the case of sunburn the mechanism is radiation.
In the case of an ice cube melting in a hand, conduction is the most important mechanism.
Answer: The correct answer is "B" two bonding domains(or bonding pairs) or two non bonding domains(or lone pairs)
Explanation:
Molecular geometry/structure is a three dimensional shape of a molecule. It is basically an arrangement of atoms in a molecule.It is determined by the central atom, its surrounding atoms and electron pairs.According to VSEPR theory, there are 5 basic shapes of a molecule: linear, trigonal planar, tetrahedral, trigonal bipyramidal and octahedral.
A)Four bonding domains and zero non bonding domains: shape is tetrahedral and bond angle is 109.5°
B)Two bonding domains and two non bonding domains(lone pairs): shape is bent and bond angle is 104.5°
C)Three bonding domains and one non bonding domain: shape is trigonal pyramidal and bond angle is 107°
D)Two bonding domain and zero non bonding domain: shape is linear and bond angle is 107°
E)Two bonding domain and one non bonding domain: bent shape and bond angle is 120°
F)Three bonding domains and zero nonbonding domain: shape is trigonal planar and bond angle is 120°
Hence Two bonding domains and two non bonding domains have the smallest bond angle.
Answer:
To find time, use this: t = d/s ( time = distance ÷ speed)
