A large unstable nucleus becomes tinier and emits an alpha
particle during Alpha decay. 4/2He or the alpha particle that consists of two
protons and two neutrons can be discharged from the nucleus during the disintegration
of radioactive decay. It has a charge of
positive 2.
Answer :
Compound : It is a mixture of elements which are chemically bonded together in a fixed proportions.
(a) Citric acid, 
In this compound, there are three types of elements present carbon, hydrogen and oxygen. There are 6 atoms of carbon element, 8 atoms of hydrogen element and 7 atoms of oxygen element.
(b) Glycine, 
In this compound, there are four types of elements present carbon, hydrogen, nitrogen and oxygen. There are 2 atoms of carbon element, 5 atoms of hydrogen element, 1 atom of nitrogen element and 2 atoms of oxygen element.
(c) Chloroform, 
In this compound, there are three types of elements present carbon, hydrogen and chlorine. There are 1 atom of carbon element, 1 atom of hydrogen element and 3 atoms of chlorine element.
(d) Sulfur hexafluoride, 
In this compound, there are two types of elements present sulfur and fluorine. There are 1 atom of sulfur element and 6 atoms of fluorine element.
Answer:
Because the number of neutrons is different, the mass number is different. Isotopes are written in two different ways. They can be written using their symbol with the mass number (to the upper left) and atomic number (to the lower left) or the isotope name is written with a dash and the mass number
Explanation:
I don't know the answer but I am sure this will help you out.
Answer:- B- 
Explanations:- Sharing of electrons takes place between non metals and the bond formed by the sharing of electrons is known as covalent bond. In first choice we only have a zinc metal and so no sharing of electrons would be possible here.
In third choice we have NaCl. Na is a metal and Cl is a non metal. The property of metals is to transfer its valence electrons to the non metal and the bond formed is known as ionic bond. So, third choice is also not correct.
In choice B we have sulfate ion that has sulfur and oxygen atoms and both of these are non metals. So, sharing of electrons is present here between the S and O atoms and covalent bonds are formed.
So, choice B-
is the right answer.