Answer:
There are 2 atoms in NaCl. This is because there is 1 atom of Na (sodium) and 1 atom of Cl (chlorine) in each NaCl molecule. Elements by themselves do not have a "number of atoms"- if you're talking about the atomic number, it's the number of protons (or electrons in a neutral atom) of an element.
A chemical change
Explanation:
In this reaction, a chemical change has occurred, here are some indicators of chemical changes from the reaction;
Chemical changes are changes in which new products are formed.
- Formation of bubbles and precipitates: these are new substances that indicates a chemical change. The bubbles and insoluble precipitate are good indicators of chemical change.
- A temperature change that is large; This is also typifies chemical changes. When temperature rises in reaction, a chemical change has occurred.
- The bubbles and precipitates cannot be combined to give the reactants. The reaction is irreversible.
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Answer:
A feasible error could have been the removal of the sample before all water evaporated.
Explanation:
In order to determine the percentage of water in an hydrate, an experiment that could be performed is the heating of the sample until the mass does not change. If the student heated the sample an insufficient amount of time, water will be present in the sample, thus reducing the percentage reported.
Length=The distance between two points
Mass=The amount of matter contained in a body
Time=The interval or duration between two events
Temperature=The hotness and coldness of a body