Suggest the methods used to separate the following:
1. paneer from curdled milk.
2. chalk powder from water.
3. sand from salt solution.
4. saw dust from water.
5. tea leaves from brew.

Separation method for various ingredients are

1. Paneer from curdled milk.  - Filtration

2. Chalk powder from water.  - Filtration

3. Sand from salt solution. - Evaporation

4. Saw dust from water.  - Skim off, sieve or filter

5. Tea leaves from brew. - Filtration.

Explanation:

By the help of a muslin cloth the paneer is separated from the curdled milk, the process is called as the filtration. The paneer will remain in the cloth and curdled milk will be removed. Separation of chalk powder from water is very easy by the process of filtration, after the filtration the chalk powder retentate and the filtrate obtained is the water in absence of chalk.  Salt and sand water separation can be done with the help of evaporation. Separation of the saw dust from water takes place by the method of sieving or sedimentation. The tea leaves are separated from brew by filtration.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

c, liquids evaporate, creating a gas