Answer:
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.
Answer:
Yes, it is standard for each element. You can calculate it from the formula: n=A-Z, where n is the number of neutrons, A is the atomic mass and Z is the atomic number.
Chemical change happens when a substance combines with
another substance to form a new substance. It produces chemical reactions and
generally is not reversible except by further chemical reactions. Heat is sometimes
produced in some reactions. When chemical reactions occur, the atoms are
rearranged and an energy change happens along with it as new products are
generations. At a molecular level, chemical changes involves the making or
breaking of bonds between atoms. Some examples of chemical change are iron
rusting (iron oxide forms) and bread rising (yeast converts carbohydrates into
carbon dioxide gas).
I would say you should use or test it once a week to ensure it is working properly in an active laboratory since it is a workplace with significant chemical hazards so it would give peace of mind to know on a quite regular basis that it can be relied on in case of an emergency like an eye flush for example.
