The two oxygen atoms share two pairs of electrons, so two covalent bonds hold the oxygen molecule together
I think it is a radiation poisoning
<u>Answer:</u> The given example is a physical change.
<u>Explanation:</u>
A chemical change is defined as the change in which chemical composition of a substance changes and results in the formation of a new substance. These are usually irreversible process.
A physical change is defined as the change in which only the shape and size of the substance changes and no new substance is formed. Only phase change occurs in these processes. These are usually considered as a reversible change.
For the given example: Moisture in the air forms beads of water on a cold window pane.
This is a physical change because water was initially present in the gaseous state (Moisture in the air) and when it is coming in contact with the cold window pane, the gaseous state of water gets converted into a liquid state.
Hence, the given example is a physical change.
The answer is na3po4+3koh=3naoh+k3po4
