Help, please. balance these equations by writing the proper coefficients in the blanks provided. 1. Mg + O2 --> MgO
2. P + O2 --> P2O5
3. S + O2 ---> SO2
4. Na + Cl --> NaCl
5. CaCO3 --> CaO + CO2

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What’s the scientific notation for the number 6,840,000,000

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.