Answer:
3,1,4,2
Explanation: the time is the longest for the liquid that has the biggest viscosity
4 covalent ---because bromine is a non-metal and each atom must share electrons in order to satisfy the octet rule. In a covalent bond, two atoms share a pair of electrons. IOnic bonds form as a result of the transfer of electrons from one atom to another.
Adding a catalyst to a chemical reaction results in a decrease in activation energy and an increase in the reaction rate.
Answer:
A
Explanation:
A. is correct
A chemical change is one in which a new substance is formed. To check if there is a chemical change when the two liquids were combined, what we simply need to do is to see if there is the formation of a new substance. The new substance formed is expected to be chemically and physically distinctive from its formative members.
B is incorrect
Being pure or impure does not provide any information if a chemical change had occurred or not.
C is incorrect
The toxicity of both doesn’t provide any information as regards if a chemical change had occurred or not
D is incorrect.
