What is observed when lead nitrate powder is heated ? What type of reaction is this?

When lead nitrate powder is heated it produces brown fumes . These fumes are of nitrogen dioxide. \( 2Pb{(NO_{3})}_{2}{(s)} \rightarrow 2PbO{(s)}+4NO_{2}{(g)}+O_{2}{(g)} \) This is the decomposition type reaction.