The answer is C) reactants because a chemical reaction is the process in which atoms present in the starting substance rearrange to give new chemical combinations present in the substance formed by the reaction
moles of CO gas : 1.545
<h3>Further explanation</h3>
Standard conditions for temperature and pressure are used as a reference in certain calculations or conditions
There are 2 conditions that are usually used as a reference : STP and RTP
Assuming the STP state :
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.
Then for 34.6 L of CO gas :

Answer: It becomes the uncombined element in the product.
Explanation:
The reaction between Zn and HCl is a single displacement reaction according to equation below
Zn + 2HCl —> ZnCl2 + H2
Zn displaces H2 from acid and in the product, hydrogen became the uncombined element.
An early model of the atom was developed in 1913 by Danish scientist Niels Bohr (1885–1962). The Bohr model shows the atom as a central nucleus containing protons and neutrons with the electrons in circular orbitals at specific distances from the nucleus . These orbits form electron shells or energy levels, which are a way of visualizing the number of electrons in the various shells. These energy levels are designated by a number and the symbol "n." For example, 1n represents the first energy level located closest to the nucleus.
Actually, I strongly believe it is a switch.