How do how do you know the number of valence electrons in an atom from the periodic table? User: How do you know the number of valence electrons from the periodic table?

What are some common tools scientists use to measure length and mass?

How many atoms are in 3 moles of carbon?

The major portion of an atomic mass consist of

If a overscript right-arrow endscripts minus b overscript right-arrow endscripts = 3.8c overscript right-arrow endscripts, a overscript right-arrow endscripts plus b overscript right-arrow endscripts = 3.

A homogeneous mixture has the same composition throughout. a. True b. False

Which of the following is true about a redox reaction? In a redox reaction, an electron is lost by the reducing agent. In a redox reaction an electron is lost by the oxidizing agent.

Is the equation above balanced? How do you know? Mg + 2HCl → MgCl2 + H2

What characteristics do atoms of carbon-12, carbon-13, and carbon-14 have in common?

Which of the following changes would decrease the rate at which a solid solute dissolves in a liquid solvent? A. Decreasing pressure B. Decreasing surface area C. Increasing rate of stirring D. Increasing temperature

Helium, neon, and argon are examples of A) metals B) metalloids C) noble gases D) transitional metals