A single atom of an element has 21 neurons 20 electrons and 20 protons which element is it?

How many different elements are in ammonium hydroxide (nh4oh) ?

Explain why the term recycling is an excellent description of plate tectonics

What is the highest electronegativity value in the periodic table?

I have a balloon that can hold 100 liters of air. If I blow up this balloon with 3 miles of gas at a pressure of 1 atmosphere, what is the temperature of the balloon

200 grams of an organic sample which contains only carbon, hydrogen and oxygen is analyzed and found to contain 97.30grams of carbon, 16.22grams of hydrogen and the remainder oxygen. what is the empirical formula for the compound?

Which earth cycle does the suns energy drive

How many moles are in 10 grams of CaCl2?

Which is the correct formula for phosphorus pentachloride? PCl4 because a subscript of 4 indicates four Cl atoms PCl5 because a subscript of 5 indicates five Cl atoms P5Cl because a subscript of 5 indicates five P atoms P5Cl3 because a subscript of

Why are the elements in groups 3 to 12 often used to make dyes?

What is not needed for corrosion of metals? a. oxygen c. water b. ions d. sunlight