Ionic compound consists of a positively charged ion and a negatively charged anion. For example, NaCl. Na (sodium) is a cation (another word for positively charged ion) and Cl (chloride) is a anion (another way for negatively charged ion.)
Molecular compounds consists of only negatively charged ions. For example Br2I is a compound of 2 elements that are negatively charged.
Unlike ionic compounds, molecular compounds consists of two or more negatively charged elements.
Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
Answer:
frequency it the measure of the wave length. The measure of the peaks and troughs is how you measure the frequency. the distance between these is the wave length.
He could be blindfolded and know which was his and which was his sister's. All he would need to do is pick them both up and if they were too big then pick them up one at a time. The lumber might make it harder to tell, but this is a question about physical properties.
So there is a change in mass which for the purpose of this question should be quite different. His sister's ought to be much lighter than his. He would find it easier to pick up.
