Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
The STP is Standard temperature and pressure.
Standard temperature is defined as zero degrees Celsius (0° C)
Standard pressure supports 760 millimeters in a mercurial barometer (760 mmHg)
we have that
760 mmHg= 1 atm
therefore
the answer is 0 deg C and 1 atm.
Answer:
Large crystals
Slowly
Explanation:
Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.
Recrystallization is also called as method of fractional crystallization.
After a recrystallization, a pure substance will ideally appear as a network of <u>large crystals</u>. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more <u>slowly</u>.
If you use up renewable resources faster than you can reproduce them, then they're really non-renewable. For example, if you're cutting down trees faster than they're growing, then you'll eventually run out of trees, even though they're "renewable". Technically, oil is renewable, but it takes millions of years to create, so it's non-renewable.
