Explain why there is a greater increase in effective nuclear charge from left to right across a period than there is for top to bottom in a group.

Question 6 A 9.0-kg crate rests on a frictionless surface. It then experiences a net horizontal force of 45. newtons. What is the resulting acceleration of the crate? A 0.0 m/s2 B 0.20 m/s2 C 5.0 m/s2 D 36 m/s2

Calculate the mass percent of phosphorus in a strand of DNA that consists of equal amounts of each of the four N-bases.

How to test for carbon dioxide

What is the molarity of formaldehyde in a solution containing 0.25 grams of formaldehyde per mL?

A mineral sample has a mass of 51 g and a volume of 15 cm3 what is the density of the mineral sample

2K3N + 3CaCrO4 → Ca3N2 + 3K, CrO Give the formula for the second reactant: How many potassium atoms on the reactant side: How many oxygen atoms on the product side?

Why does aluminum most often have an oxidation state of + 3

In the thermal decomposition of copper carbonate, the black solid left behind weights less than the original copper carbonate. Why?

How many joules are needed to warm 675 grams of water (specific heat = 4.186 J/g degrees Celsius) from 12 degrees Celsius to 85 degrees Celsius?

Pentaborane b5h9 (s) burns vigorously in o2 to give b2o3 (s) and h2o (l). what is δh° for the combustion of 1 mol of b5h9 (s) ? substance δh°f (kj/mol) b2o3 (s) - 1273.5 b5h9 (s) + 73.2 h2o (l) - 285.8