‘2’AgNO3 + Cu -> Cu(NO3)2 + ‘2’Ag
Explanation:
In any chemical change, one or more initial substances change into a different substance or substances. ... According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and kind of atoms after the chemical change as were present before the chemical change
Example:
The carbon atom in coal becomes carbon dioxide when it is burned. The carbon atom changes from a solid structure to a gas but its mass does not change.
It can be an element or a compound
Answer:
of different elements with different electronegativities
Explanation:
A molecule containing two atoms "of different elements with different electronegativities"
A polar covalent bond exists when two different atoms (non-metals) with different electronegativities are able to share their electrons in a covalent bond.
Some examples of polar covalent bonds are seen in:
1. Ammonia(NH3): The polar covalent bonds exists between the nitrogen and hydrogen atoms.
2. Water(H2O): The polar covalent bond exists between hydrogen and oxygen. The oxygen molecule has a net negative charge while the hydrogen atoms have a net positive charge.