Read the given expression.
X = number of protons - number of core electrons
Which of the following explains the identity of X and its trends across a period?
X is the effective nuclear charge, and it remains constant across a period.
X is the screening constant, and it remains constant across
period.
X is the effective nuclear charge, and it increases across a period.
X is the screening constant, and it increases across a period.

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. in the first step, calcium carbide and water react to form acetylene and calcium hydroxide: cac2 (s) + 2h2o (g) → c2h2 (g) + caoh2 (s) =δh−414.kj in the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6c2h2 (g) + 3co2 (g) + 4h2o (g) → 5ch2chco2h (g) =δh132.kj calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. round your answer to the nearest kj .