<u>Answer:</u> The gas produced when sodium phosphide reacts with water is phosphine.
<u>Explanation:</u>
When sodium phosphide reacts with water molecule, it leads to the production of flammable, poisonous gas known as phosphine along with the production of sodium hydroxide.
The chemical reaction for the reaction of sodium phosphide with water follows the equation:

By Stoichiometry of the reaction:
1 mole of sodium phosphide reacts with 3 moles of water to produce 1 mole of phosphine gas and 3 moles of sodium hydroxide.
Hence, the gas produced when sodium phosphide reacts with water is phosphine.
Answer: d. both (b) and (c)
Explanation:
Atoms are too small to be seen on microscopes, so we model them based on theories.
Answer:
a small medical thermometer with a short but finely calibrated range, for taking a person's temperature.
Answer:
to collect measurable, empirical evidence in an experiment related to a hypothesis the results aiming to support or contradict a theory.
Explanation: