Answer:
Yes, it's an exothermic reaction, which means that energy is being released, thus it is a chemical reaction.
Explanation:
Answer 1: Atoms gain valence electrons to form anions.
Explanation:
Anions are negatively charged species of an ions. Anions are formed when atoms with nearly complete octet gains electrons.
Answer 2: Emission spectrum
Explanation:
When ever electron jumps from higher energy to lower energy level energy is emitted out in the form of light.The wavelength of the light is given as
:
, E = energy, c= speed the light, h= planck constant
Answer 3: Two atoms of silicons could combine by fusion in order to create nickel.
Explanation:
Silicon has atomic number of 14 with atomic mass of 28 u.
nickel has atomic number of 28 with atomic mass of 59 u.
Two different isotopes of silicon atom will fuse together to give nickel.

Answer: A) Na+ and O2-
Explanation:
To know the electronic configuration, one has to determine the numbers of electrons present in each atom.
Na+ means a sodium atom that has lost one valence electron. A Sodium atom initially has 11 electrons, but having lost an electron making it 10 electrons remaining with electron configuration of 1s2 2s2 2p6.
O2- means oxygen atom that has gained two valence electrons. An oxygen atom initially has 8 electrons, having gained two electrons makes it 10 electrons with electron configuration of 1s2 2s2 2p6. same as Na+
The purpose of gaining or losing electrons is to attain a stable duplet or octet structure.
The concentration of [Sn⁺²] will be calculated by first calculating the moles of SnCl₂ added as these moles will give us the moles of [Sn⁺²] ion.
Moles of SnCl₂ = molarity X volume = 0.04 X 2.60 = 0.104 milli moles [as volume is in mL]
The moles of [Sn⁺² = 0.104 mmol
the total volume in solution = volume due to MO + volume due to SnCl₂ + volume due to HCl + volume due to NaCl
Total volume = 8+2.60+5.43+3.73= 19.76 mL
Concentration = moles / volume
concentration [Sn⁺²] = 0.104mmol / 19.76 mL = 0.0053 mol / L
The word elliptical refers to an Oval.