What are three signs that a chemical reaction has taken place?

Answer 1

God is the only thing left for the human beings to believe in. Strange ! Isnt it?

Answer 2

Signs of a Chemical Changes

You can tell whether a chemical reaction has taken place by these three signs;

One or more new chemical substances are formed
The products have changed form and appearance. For example;

iron + sulphur = iron sulphide

(Black fillings) (Yellow powder) = (Black solid)



Energy is taken in or given out, during the reaction.
A reaction, which gives out heat energy, is known as exothermic (link).

A reaction, which takes in heat energy, is endothermic (link).

For example:

Fireworks are exothermic, as is the reaction above.

Frying eggs is an endothermic reaction.

Reactions not only produce heat but light and sound.



The change is usually difficult to reverse.
Several reactions would have to be carried out to get iron and sulphur from iron sulphide.

Answer 3

A precipitate varieties, warmth is stepped forward, formation of a gas. If a precipitate varieties for sure something new is made that isnt soluable anymore, which includes one produced from barium chloride into barium sulphate precipitate. An occasion of warmth being stepped forward is the addition of water to any concentrated acid as an exothermic reaction. An the formation of a gas is a sparkling product formed threw chemical reaction such because of fact the formation of HBr gas threw the reaction of Butanol and Sodium Bromide

Answer 4

A chemical change has occurred if there is heat given off, a color change, a precipitate formed, a gas formed

Answer 5

1) You here a loud bang followed by an uncanny silence as everything seems foggy and in slow motion around you.

2) The smell of sulfur is almost unbearable; and, my face and hair are blackened and blown back by the force of the blast.

3) The moaning of those that were nearby, slowly picking themselves off the floor.

...and that was me simply making eggs for breakfast!

Answer 6

1. When you put your nose up to the steam and you throw up

2. When you hear a bubba lubba bubba lubba

3. When you see a green goo oozing out off the edges and a little man jumps at ya!

Answer 7

gets hotter, gets colder, produces something else, gives off light,

Answer 8

changed into something Elise, it have off heat , it's been a while

Answer 9

Change in temperature, mass, change in volume.

Answer 10

You cough.