D phenolphthalein is the answer
Water is the answer because the word <span>Hydroelectric has hydro in it and hydro= water.</span>
Question 17
The subscript 2 is the atomic number for helium and subscript 4 is the mass number for Helium
<u><em>explanation</em></u>
when writing down an isotope of an element the mass number of that isotope is written in upper side of the chemical symbol, while atomic number is written on the lower side.
Since 4 is on upper side it is the mass number of He, while 2 is the atomic number since it is on lower side.
Question 18
The type of radiation emitted when polonium -212 form lead 208 is an alpha particle
<u><em>explanation</em></u>
Alpha decay is a decay in which an atomic nuclei emit an alpha particles and be transformed into different atomic nuclei with a mass number that is reduced by 4
polonium 212 is reduced by 4 to form lead 208 therefore it undergo alpha particle decay.
Answer:
2:A handwarmer gets warm when it is opened and exposed to air.
3:Propane ignites to heat a grill.
4:Cotton is dyed red to make a dress.
Explanation:
The definition of a chemical property is when a property of characteristic of a substance that is <em><u>observed</u></em> during a reaction in which a chemical has been changed
Answer and explanation:
The nuclides with the same atomic number, but different mass numbers are isotopes.
So, in this case, each species will have the same atomic number and a different mass number, that will be the same that it is written in the name of the element:
