Answer:
litmus paper turns red under acidic conditions
Explanation:
Ni solution could be used to remove lead from lead (II) nitrate.
Explanation:
The removal of lead from lead nitrate will take place by displacement reaction.
In displacement reaction less reactive element is displaced by more reactive element form it compound.
The reactivity is decided by the placement of metal in the activity series.
A metal which is at higher position in the activity series will be able to displace the metal or element having lower position.
From the options given we will check their position in the activity series in comparison to Pb
Cu is lower in series than Pb hence cannot displace.
Hg is placed lower in the series than Pb hence cannot displace Pb.
Ag is placed lower than Pb in the series hence cannot displace Pb.
Ni is placed above the Pb in activity series hence can displace lead.
There are 2 valence elcetrons
Answer:
Every element has a proton, neutron, and electron. The number of protons is equal to the atomic number, and the number of electrons is equal to the protons unless it is an ion.
Answer:
Thermal decomposition
Explanation:
Calcium carbonate can be broken down by heating. The following equation represents this chemical change.
CaCO₃(s) ⇒ CaO(s) + CO₂(g)
The scientific term for this process is thermal decomposition.
- Thermal refers to the fact that heat is required.
- Decomposition refers to the kind of reaction in which a big substance breaks down into smaller substances.
