If a chemical change has taken place, which of these is most likely true? It's for science.

An unknown substance has a mass of 18.3 g. When the substance absorbs 1.647*102 j of heat, the temperature of the substance is raised from 25.0 ∘c to 45.0 ∘c. What is the most likely identity of the substance?

What is the mass % of iron in Fe (CH3CO2) 2 (Fe=iron=55.85)

Write the symbolic notation of an isotope of an element having 8 protons, 8 electrons, and 9 neutrons

Is ice cream a mechanical mixture or solution why?

What is the density of a cube that has a mass of 25 grams and a volume of 125cm

For the baeyer-villiger oxidation of cyclohexyl methyl ketone

What will happen if the density of an object is less than the density of water?

Which cannot be separated into simpler substances? compound element solution mixture

What jobs involve chesmistry

Think about a neutral magnesium atom. Then think of a magnesium ion with a 2+charge. How are these two alike? How are they different? Be sure to use the terms proton, neutron, and electron in your answer.