What element has 4 valence electrons and is in period 6

Which of the following is an example of pseudoscience? A) Astronomy B) Astrology C) Vulcanology D) Hydrology

Can the anion affect color of a solution

Which is the equation of a circle with its center at (-4,2) and a radius of 4? Select one: a. (x+4) 2 + (y-2) 2 = 16 b. (x-4) 2 + (y+2) 2 = 16 c. (x-4) 2 + (y+2) 2 = 4 d. (x+4) 2 + (y-2) 2 = 4

What is the wavelength (in nanometers) of light having a frequency of 3.9 x 1013 Hz?

When 2 crystalline solid barium hydroxide octahydrate and crystalline solid ammonium nitrate are mixed in a beaker at room temperature, a spontaneous reaction occurs. the temperature of the beaker contents rapidly falls to below 0º c.

Why do elements within a period of the periodic table have different properties

A professional technician maintains and operates specialized scientific equipment. True False

What is the distance from the highest part of one wave to the highest part of the next wave.

Calculate Delta E when 33.0 g of carbon dioxide sublimes at 77.0 K and 1 ATM

Calculate zeff for a valence electron in an oxygen atom.