How many valence electrons does Iron (Fe) have? How do you know?

Are these mixtures or pure substance? 1. water 2. blood 3. the oceans 4. iron 5. brass 6. uranium 7. wine 8. leather 9. table salt (NaCl)

Why does the temperature remain constant during melting till all the ice has melted?

What is the name of the state when electrons absorb energy and move to a higher energy level? illuminated state excited state diffused state ground state

A PNP transistor is connected in a circuit so that the collector-base junction remains reverse biased and the emitter-base junction is forward biased. This transistor can be used as a power amplifier because

With what elements does nitrogen form ionic bonds?

List two potential problems with burning garbage.

Mole ratios how can the coefficients in a chemical equation be interpreted. True or False

For taking sip of hot tea, we blow air on it. Justify

The molecules in a solid object A. flow freely around each other B. vibrate slowly C. are completely still all the time

How many moles of water can be obtained from the reaction of 4 moles of O2?