the number of atoms? if the chemical change happens in a closed space, all the atoms are still present in one form or another. In another words, chemical reactions follows the principle of conservation of mass. This principle is founded on the assumption that matter can neither be created or destroyed. Thus, the total mass of all compounds prior to the chemical change/reaction should be the same as the total mass of all compounds after the chemical change.
example: you burn wood, it releases all kinds of chemicals in the smoke, water vapor, and ashes. if you could collect all the water vapor and the smoke, you would still have the same number of atoms - now they would have less energy (since the heat produced from burning them is gone) but there would still be the same number of atoms, albeit in different compounds probably.
I think it is State of matter Stays the same.
physical because a chemical change means it can never form back
Physical.
No new substances are formed in physical changes. A existing substance may change forms (liquid water may turn to water vapour or ice) but a new substance is never formed.
i have a good friend who has had diabetes for many years and its never changed his voice.
No, all changes of state are physical, never chemical. It always can be reversed by temperature change only and no other compound are involved.
A physical change can be reversed, for it does not change what the object is made of. The glass, even when broken, is still glass. It can be put back into its original state (possibly through melting) because it never changed what it was made out of.
No. In a physical change, the substance maintains its chemical composition.
When a aluminum can is crushed, it undergoes a physical change, because even though the object got crushed and misshaped it still has the same identity.The identity has never changed.
It depends if the change is physical or chemical. If it is a physical change, the wood or iron never really changed, just it's physical appearance. If the change is chemical then the wood or iron supposedly can't change back to it's original substance or matter.
An aggregate constant is a nonscalar constant which value never change or are not changed during execution of the program.
Germany's name never changed during the Holocaust.
physical because a chemical change means it can never form back
physical because a chemical change means it can never form back
Physical.
There were many things that changed during the Renaissance. Such as the art, literature, and even religion which would have never be allowed in medieval times. The Renaissance was a whole change of mind. :)
He never changed his name.
physical because a chemical change means it can never form back