Answer:
2NaBr + I2 Right arrow. 2NaI + Br2
2AgNO3 + Ni Right arrow. Ni(NO3)2 + 2Ag
Explanation:
The activity or electrochemical series is an arrangement of elements according to their order
of reactivity.
If we look at the reactions, one thing that we must note is that the reactions that can occur are those in which an element that is higher in the series displaces another element that is lower in the series.
Br is higher in the electrochemical series than I so it can displace it. Ni is higher than Ag in the electrochemical series hence it can displace it.
Actually, there are only about 100 atoms that have been yet discovered. But each element has many different kinds of atom. For instance, carbon. Do you know carbon has more than 30 or 50 different types of atoms? Well, how? There are isotopes. Don't think that there is only one carbon atom which has 6 electrons and 6 protons and 6 neutrons. There are more. C-13 has 6 electrons and 6 protons and 7 neutrons. While, C-14 has 6 electrons and 6 protons and 8 neutrons. I just showed you three stable isotopes of carbon(element). But, what is really an isotope?? Did you notice that all of these atoms had the same number of protons and electron but different numbers of neutrons? This is really an isotope. Well, if an atom takes a few more electrons or gives off a few electrons, it still stays the same element/ atom type. Just like that an element can have atoms of different neutron number. It may be less or more. It doesn't affect the atom much: just makes an isotope. But it does affect the atomic mass number or radioactivity of an atom. So, an element can have many different forms of isotopes of its atoms. In this way, being only 100 atoms, there can 1000 atoms or (more than that!).
To make it more clear-
Definition of ISOTOPE: <span>any of two or more forms of a </span>chemical<span> element, having the same number of protons and electrons in the nucleus, or the same atomic number, but having different numbers of neutrons</span>
HOPE YOU UNDERSTOOD THE MATTER:-))
It would use rapid combustion
Mass is measured by using a balance