What are 3 signs that a chemical change (chemical reaction) has taken or is taking place?

Where do people and other animals get energy to move around

3. Sodium carbonate (Na2CO3) is formed from the reaction between O A a weak acid and a strong base B a strong acid and a strong base C a strong acid and a weak base OD a weak acid and a weak base

An alkane used as a lubricant contains 25 carbon atoms. How many hydrogen atoms are present in its structure?

If steel (a metal) is hard and granite (a nonmetal) is hard, why don't we make automobile engines out of granite?

How many moles are in 5g of NaOH

chromium can combine with chlorine to from corneum chloride which equation is a correct representation of this reaction

What is the atomic weight of a hypothetical element consisting of two isotopes, one with mass = 64.23 amu (26.0%), and one with mass = 65.32 amu? (a) 65.3 amu (b) 64.4 amu (c) 64.9 amu (d) 65.0 amu (e) 64.8 amu

Is this base a physical or chemical property?

Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte. a) LiClO4 b) HClO c) CH3CH2CH2OH d) HClO3 e) CuSO4 f) C12H22O11

Give examples of temporaty physical change