Which of the following statements about alkali metals is true?

alkali metals have full valence shells

alkali metals form 1 - cations

alkali metals are very reactive

alkali metals form 2 - cations

If a neutral atom of oxygen (O) has 8 protons, 8 electrons and 7 neutrons, what is the mass number of this atom? A. 8 B. 15 C. 16 D. 23

Why do you think that if you drop two balls, exactly two balls rise on the other side at a similar speed? Why doesn't one ball fly off quickly instead? Why don't three balls fly off slowly?

A 0.600 g sample of a compound of arsenic and oxygen was found to contain 0.454 g of arsenic. What is the empirical formula of the compound? * A. AsO2 B. As2O C. As2O3 D. AsO

If you combine 350.0 mL of water at 25.00 °C and 120.0 mL of water at 95.00 °C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.

The most common substance on earth is water. True Or False

Suppose that you measure a pen to be 10.5 cm long. Convert this to meters.

How are amounts of hydrogen and oxygen gas made from the electrolytic decomposition of water related to the chemical formula of water?

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 2H2O2 (l) → 2H2O (l) + O2 (g) ΔH = - 196 kJ Calculate the value of q (kJ) in this exothermic reaction when 3.

What is the concentration of hydronium in each of the following cases: [OH-] = 10-12 M? [OH-] = 10-2 M?

Which statement best explains why elements are matter? An element is a physical substance that has mass and takes up space. Elements are pure substances that cannot be divided chemically. Each element is a pure substance composed of one type of atom.