1. neutron
2. proton which is positive
3. electron which is negative
Answer:
so like Each of the five states of matter collectively made up all the "stuff" that's in the universe- — everything that takes up space and has mass is matter,and All matter is made up of atoms and in turn made up of protons and neutrons and electrons.
Explanation: hope this helps
Density as you say Saturn as you say Jupiter as you say big stuff chemistry mike h20 is water
Answer:
- <u><em>It is positive when the bonds of the product store more energy than those of the reactants.</em></u> (the second statement)
Explanation:
ΔHf is the change of enthalpy during the reaction, which is equal to the sum of enthaply changes of the products less the sum of the enthalpy changes of the reactants.
- ΔHf = ∑ (ΔH products) - ∑ (ΔH reactants)
Also, ΔHrxn, per definition, is the potential chemical energy stored in the bonds of the products less the chemical potential energy stored in the bonds of the reactants.
Then, when the potential chemical energy stored in the bonds of the products is greater than the chemical potential energy stored in the bonds of the reactants ΔHrxn is positive.
Hence, you conclude that ΔHf is positive when the bonds of the product store more energy than those of the reactants (second statement from the choices).
Some brief comments about the other statements:
- The standard enthalpy of formation, ΔHf, is zero for an element in its standard state, not for a compound.
- For a compound the enthalpy of formation at 25ºC and 1 atm (the standard state) may be positive or negative.
- Also, note that the standard state for any element is not liquid: some are solids, some are gases, and some are liquids at 25ºC and 1 atm.
Answer is potassium and sodium. They are in the same group and that means they have the same properties. They are all alkali metals
