Answer : The correct option is, Electron.
Explanation :
There are three subatomic particles of an atom which are electrons, protons and neutrons. The protons are positively charged, the electrons are negatively charged and neutrons are neutral (no charge).
A neutral atom is an atom that has same number of electrons and protons. When a neutral atom gain an electron, it becomes a negatively charged ion. When a neutral atom lose an electron, it becomes a positively charged ion. That means the atom change when the electron is lost or gained.
Hence, if the atom undergoes a change and becomes a positive ion, in this process the lost subatomic particle is electron.
Answer : The radiation which is smallest in the size is, Gamma radiation.
Explanation :
Alpha particle : It is also known as alpha radiation or alpha ray that consists of 2 protons and 2 neutrons that are bound together into a particle that is identical to the helium nucleus. It is produced in the process of alpha decay.
Beta particle : It is also known as beta radiation or beta ray. During the beta decay process, a high energy and speed electron or positron are emitted by the radioactive decay of atomic nucleus.
Gamma particle : It is also a gamma radiation or gamma ray that is arising from the radioactive decay of atomic nuclei. It has shortest wavelength waves and imparts high photon energy can pass through most forms of matters because they have no mass.
The increasing order of the particle size of the alpha, beta and gamma particles will be :
Gamma particle < Beta particle < Alpha particle
Hence, the radiation which is smallest in the size is, Gamma radiation.
B)
sulfur, selenium, polonium, 6
Eliminate
C)
hydrogen, fluorine, potassium, 1
D)
calcium, phosphorus, tellurium, 2
The correct option is B.
Sodium will react with elements in GROUP 6, WHICH HAVE SIX ELECTRONS IN THEIR OUTERMOST SHELLS.
Sodium is a metal with atomic number 11. The electronic configuration of sodium is 2,8,1. This implies that, sodium has one electron in its outermost shell. Sodium always donate this electron in order to become stable. Elements in group 6 have six electrons in their outermost shells and they require two more electrons to attain stability. In order to form chemical bonds with elements from group 6, two atoms of sodium will react with each atom of those elements, that is, the ratio of reaction will be 2:1. By so doing, the two sodium atoms will be the ones that will donate the two electrons that the group 6 elements need to attain stability. One example of compounds formed by such reaction is sodium sulfide, Na2S.
_Fe + _H₂SO₄ -> Fe₂ (SO₄)₃ _ H₂