Cathode rays are a stream of negatively charged particles or electrons in vacuum tubes. They were first seen by Johann Hittorf in 1869. They are named since they are emitted by electrode or cathode. In order to release the electrons, the electrons should first be detached from the atoms of the cathode.
C. low boiling points, since convalent bonds are comprise of two non metal elements, the have relatively low boiling points, since most of them are gases.
Answer:
Option "B" is correct.
Explanation:
According to VSEPR theory, There are repulsion forces exists among the bond pair - bond pair or bond pair - lone pair of electrons. In
and
, the number of electron pairs are same but methane has all the four bond pairs where in ammonia, three bond pairs and one lone pair exists. And thus there are repulsion forces possible in between the lone pair and bond pair of electrons thus the arrangement of electron pairs around both the molecules is same or different depending up on the conditions leading to maximum repulsion.
Answer: The molecular formula will be 
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
The empirical formula is 
The empirical weight of
= 1(12)+3(1)= 15g.
The molecular weight = 45.0 g/mole
Now we have to calculate the molecular formula:

The molecular formula will be=
Thus molecular formula will be 
Answer:
its none above
Explanation:
food webs have arrows that show the flow of energy from one orhganism to the next
bar graphs have bars and numbers and diagrams have words and pictures so it D