To tell if a chemical reaction has occurred look for these four things:
1) color change
2) the formation of gas bubbles
3) formation of a precipitate
4) temperature change
Formation of bubbles or gas: Gas evolution can indicate a chemical reaction is occurring. Change in color: A sudden change in color could be a sign of a reaction, such as a shift from clear to cloudy. Temperature change: If the reaction generates heat (exothermic) or absorbs heat (endothermic), it can be an indication that a chemical reaction is taking place.
Phase changes are one example of a non chemical change. If the substance reacts the same way chemically, it has the same properties such as melting point, there has not been a chemical change.
Bubbles
The reducing agent list for a chemical reaction includes substances that donate electrons to other reactants, causing them to be reduced. Common reducing agents include metals like zinc, magnesium, and aluminum, as well as compounds like hydrogen gas and carbon monoxide.
Because Gold is an extremely unreactive metal, which means that it is not found in any compounds, e.g. Gold Oxide, but is only found on its own. So no chemical reaction is needed to obtain gold. Also, if you look at a metal reactivity series, gold will be at the bottom of the list.
list four possible clues to a chemical change
Formation of bubbles or gas: Gas evolution can indicate a chemical reaction is occurring. Change in color: A sudden change in color could be a sign of a reaction, such as a shift from clear to cloudy. Temperature change: If the reaction generates heat (exothermic) or absorbs heat (endothermic), it can be an indication that a chemical reaction is taking place.
flammability density smoke burned
Phase changes are one example of a non chemical change. If the substance reacts the same way chemically, it has the same properties such as melting point, there has not been a chemical change.
Bubbles
The reducing agent list for a chemical reaction includes substances that donate electrons to other reactants, causing them to be reduced. Common reducing agents include metals like zinc, magnesium, and aluminum, as well as compounds like hydrogen gas and carbon monoxide.
A catalyst alters (usually increases) the speed of a chemical reaction in which there is no net change in the amount of catalyst present after reaction is complete.
The list that indicates which metals are able to displace other metals in a chemical reaction is called the activity series. It ranks metals in order of reactivity, with more reactive metals displacing less reactive metals in aqueous solutions.
An endothermic reaction is any chemical reaction that absorbs heat from its environment. Here's a list of examples of endothermic reactions. You can use these when asked to cite an example or to get ideas to set up a demonstration of an endothermic reaction or process.
anne cahill
You did not write any of those chemical names correctly (methane is CH4, not ch4) and all you did was list 4 incorrectly written chemicals, you did not give a chemical equation. Only a chemical reaction can be described as endothermic or exothermic; chemicals by themselves do not have those properties.
follow the clues and when you get to the list of numbers call that number and the follow more clues finally you will find the diary in the math room