"Metals are usually not found as nitrates in their ores'"

Out of the following two (I and II) reasons which is/are true for the above observation?

I. Metal nitrates are highly unstable.

II. Metal nitrates are highly soluble in water.

1. I and ll are true 

2. I and II are false

3. I is false but ll is true

4. l is true but ll is tase

In the case of alkali metals, the covalent character decreases in the order

1. MCl>MI>MBr>MF

2. MF>MCl>MBr>MI

3. MF>MCl>MI>MBr

4. MI>MBr>MCl>MF

Ionic mobility of which of the following alkali metal ions is lowest when aqueous solution of their salts are put under an electric field?
1. K
2. Rb
3. Li
4. Na

The suspension of slaked lime in water is known as:
1. lime water
2. quick lime
3. milk of lime
4. washing of lime

In context with beryllium, which one of the following statements is incorrect?

1. It is rendered passive by nitric acid
2. It forms ${\mathrm{Be}}_2\mathrm{C}$
3. Its salts rarely hydrolyze
4. Its hydride is electron-deficient and polymeric

The most acidic oxide among the following is - 
1. MgO
2. BeO
3. BaO
4. CaO

The product obtained as a result of a reaction of nitrogen with CaC₂ is:

1. CaCN
2. CaCN₃
3. Ca₂CN
4. CaCN₂

Which of the following statements is false?
 

A compound that releases CO₂ most easily upon heating is?
1. $K_{2}C{O}_3$
2. $N{a}_{2}C{O}_3$
3. $MgC{O}_3$
4. $CaC{O}_3$

Which of the following biologically important ions is also a constituent of the sodium pump?

1. Ca²⁺
2. Mg²⁺
3. K⁺
4. Fe²⁺