Potassium Hydroxide (KOH) when added to the solution would give the highest pH
Explanation:
Bases or Alkali are associated with high pH while Acidic substances are represented by lower pH value.
In the given option
HCl- is a strong acid hence would have pH less than 7
H2SO4- also an acid with a pH less than 7
KOH- base with a pH higher than 7
H20-neutral compound with pH as 7
KOH is a very strong base and dissociates in aqueous solution to give it's corresponding metallic ion and hydroxyl ions (OH-) which are characteristic property of any base.
Carbon (from Latin: carbo "coal") is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table.
<span>A physical change basically involves a change in physical properties. Some examples of physical properties include: texture, shape, size, color, volume, mass, weight, etc.
The water melting has changed the shape and therefore it's physical properties, but the chemical nature of the water has not been altered.
So that's why it's a physical change, and not a chemical change.</span>
<h2>Ultraviolet Light</h2>
Explanation:
- The energy of a photon that will be released if an electron falls from the n= 2 orbit (excited state) to the n0 = 1 orbit (ground state) is of ultraviolet light.
- In the ultraviolet part of the spectrum, a photon having an energy of 10.2 eV has a wavelength of 1.21 x 10-7 m.
- Hence, when an electron wants to jump or it gets excited from the first level to the second level that is from n = 1 orbit to n = 2 orbits, it must absorb a photon of ultraviolet light.
- But,When an electron falls from n = 2 orbit to n = 1 orbit or from n = 2 orbit(excited state) to n = 0 orbit(groubd state), it emits a photon of ultraviolet light.
