C)crabon,oxygen and calcium
Answer:
Main group elements, the transition metals, the lanthanides, and the actinides.
Explanation:
Answer:
The mechanical properties of urea formaldehyde resins may be improved by incorporating therein polyvinyl alcohol. The polyvinyl alcohol may be incorporated during pre-mixing, mid mixing, and/or post mixing of the resin components. Resins prepared using polyvinyl alcohol are particularly desirable in articles requiring improved mechanical strength and water resistance, as compared to similar resins prepared without the polyvinyl alcohol such as shingles.
The number of protons uniquely identifies the element. This is not on the periodic table. Isotopic notationincludes the atomic number and the mass number. 8 17 This isotope of oxygen has 8 protons (atomic number), 8 electrons and 9 neutrons