Answer:
evaporation, vaporisation, boiling if change occurs at boiling point
Explanation:
Answer:
Francium (Fr)
Explanation:
From the given choices, francium will have the lowest ionization energy.
Ionization energy is the energy required to remove the most loosely held electron within an atom.
The magnitude of the ionization energy depends on the characteristics of the atom in relation to its nuclear charge, atomic radius, stability etc.
- Generally on the periodic table, ionization energy increases from left to right on the table
- As you go from metals to non-metals and to gases, the value of the ionization energy increases steadily.
- Down the group, the value reduces.
- Since Francium is the most metallic of all the given choices, it has the highest ionization energy.
Answer:
Buffers are resistant to high pH changes.
Explanation:
This perfectly explains the reason why we use buffers. Buffers are substances which consist of a weak acid and its conjugate base. Buffers are resistant to significant pH changes upon addition of strong acids or bases. To illustrate this, let's say we have a buffer consisting of 0.1 mol of HF, a weak acid, and 0.1 mol of NaF (fluoride is a conjugate base of HF).
- Let's say we add some strong acid, in a general form, this acid would be represented as . In this case, conjugate base will react and neutralize it to produce some amount of HF: .
- Similarly, if we add some strong base , the acidic component will react with it to produce some amount of conjugate base: . The ratio of HF to NaF in this case is held around the same value for addition of small amounts of strong acids/bases, so pH is kept almost constant, while in neutral water, pH would drastically increase or decrease.
Answer:
drought
Explanation:
droughts are long periods without water