An atom of potassium has 19 protons and 20 neutrons. what is its mass number?

A machine has an efficiency of 70%. How much woke does the machine do when 20,000 J of work is done on it?

Can someone complete the chemical reactions, or write which one do not occur, and provide tehir types? *c2h4+h2o *c3h8 + hcl *c2h2+br2 *c4h10+br2 *c3h6+br2

How many significant figures are in the measurement 33,050 grams?

How many molecules are in 0.25 moles of CH4

An ebony carving has a mass of 267g and a volume of 207cm^3 what is the density?

Identify the property of magma that causes it to be forced upward towards earth's surface.

Classify each of these compounds as a Brønsted-Lowry acid, a Brønsted-Lowry base, or neither. Drag each item to the appropriate bin. are these a Brønsted-Lowry acid or a Brønsted-Lowry base H2SO4, HNO2, (CH3) 3N, C3H7NH2, HF, NH3, NaBr, CCl4

If you dissolve sugar into water in a small jar, will the result be a mixture, a solution or both? Explain.

Convert the following energy units. 635 kJ to J

What is the element K2SO4 and is it ionic, covalent or polyatomic