The tendency to combust is a chemical property.
O True
O False

The correct option is;

True

Explanation:

Combustion is a chemical reaction between components of a combustion reaction which are;

1) A fuel

2) An oxidizing agent

The oxidizing agent or oxidant in a combustion reaction consist mainly of oxygen.

A combustion reaction is an oxidation and reduction (redox) heat evolving (exothermic) reaction that takes place at high temperatures and produces smoke which consists of gaseous mixture of chemicals and sometimes very small solid particles

An exothermic reaction can be classed either as rapid, spontaneous, or explosive

A spontaneous exothermic reaction is one that begins on its own in atmospheric conditions and room temperature as the heat required to begin the reaction is produced by the initial oxidation of the reacting fuel

Example of a substance that undergoes spontaneous oxidation reaction is white phosphorus.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.