The mass of an atom comes from
the protons and neutrons that are found in the nucleus. The number of protons
is the atomic number of an element. To find the number of neutrons, subtract
the atomic number from the mass of an atom. So, if an element is 76, the number
of protons AND electrons is also 76.
Answer:
1.08 g/mL
Explanation:
Density=Mass/Volume therefore you would do the mass which is 7.481 g divided by the volume which is 6.9 mL and get 1.08 g/mL since you combine the two labels!
Answer:
dispersion, dipole-dipole, and hydrogen bonding
Explanation:
The pictured compound is an amine. Amines have high boiling points. Amines have such high boiling points because they posses about three different kinds of intermolecular interactions, viz; hydrogen bonds, dispersion forces and dipole-dipole interactions.
The dipole interactions and hydrogen bonds arise from the fact that the N-H bond is polar. Also recall that a hydrogen bond is formed when hydrogen is bonded to an electronegative element. Hydrogen bonds lead to significant intermolecular association and high boiling points.
Hence the three kinds of intermolecular forces present in the pictured compound are; hydrogen bonding, dipole interactions and dispersion forces.
The answer is; D
While electromagnetic waves travel at an astounding 3.00 x 10^8 m/s and any delay seems imperceptible in short distances, in long distances, the waves take some time to reach the other end. This is why there is usually a small delay when ground communication tries to reach astronauts in space. Also, remember that when a communication is relayed from the earth, it has to reach the destination and then wait for a response back to earth which covers the same distance or longer/shorter if the target is moving.
The distance to the moon is 384,400 km, therefore multiply this by 2 = 768,800 km
768,800,000m/300,000,000m = 2. 56 seconds
Therefore radio waves sent to the moon from earth will have a minimum 2.5 seconds delay not considering the processing time of this communication by the destination before sending feedback. ‘Over to you’ signals end of a message by the messenger hence allowing the other messenger on the other to respond.
