Answer:
.
Explanation:
Lithium is in the first column of the periodic table, so it will have 1 valence electron.
Bromine is in the seventh column of the periodic table, so it will have seven valence electrons.
They must combine in a way to reach 8.
When combining elements to form compounds, the "crisscross method" is used. Above Li would be a charge of +1, and above Br would be a charge of -1.
Cross the 1 from the top of Li to the bottom of Br, and so there is 1 Br.
Cross the 1 from the top of Br to the bottom of Li, and so there is 1 Li.
It is not written BrLi because chemists decided to order them the other way. Technically speaking, it isn't wrong, but the positive charge is normally put on the left and the negative charge is normally put on the right.
Answer:
This tells us the radial velocity of the object and that the object is approaching or coming towards us.
Explanation:
Certain chemicals radiate with particular wavelengths or colors when their temperature is raised or when they are charged electrically. Also observable are dark strokes separating the spectrum known as absorption lines
These spectral lines of chemicals are well known as stated above and from the phenomenon of Doppler effect, spectroscopy can be used to detect the movement of a distant object by the change of the emitted frequency of the wavelength
The Doppler effect is used in calculating the radial velocity of a distant object due to the fact that an approaching object compresses its emitted signal wavelength while a receding object has a longer wavelength than normal
Answer:
I remember doing this in 7th,
1. D
2. B or D, more leaning on B though
3. A
