An ion of zinc, Zn, has 28 electrons, 30 protons and 33 neutrons. What is its mass number

A conducting sphere has a net charge of - 6.4 * 10-17 c. What is the approximate number of excess electrons on the sphere?

Hydrogen reacts with chlorine to form hydrogen chloride (HCl (g), Delta. Hf = - 92.3 kJ/mol) according to the reaction below. Upper H subscript 2 (g) plus upper C l subscript 2 (g) right arrow 2 upper H upper C l (g). Which statement is correct?

Which of these molecules are polar? check all that apply.

4.5 * 1025 atoms of nickel equal how many moles? A. 27 mol B. 2.7 * 1048 mol C. 0.75 mol D. 75 mol

When these bond to make ccl4, what is the shape of a ccl4 molecule? linear circular tetrahedral trigonal planar

Draw the condensed structural formula for the ammonium salt formed when lidocaine reacts with hcl.

Where might you find a temperature of 2 kelvin? a. north poleb. the equatorc. earth's cored. the coldest regions of outer space

A blank is a coil of wire that produces a magnetic field when it carries an electric current

What is the change in heat energy when 132g of copper at 32.2°C is raised to 45.0oC? The specific heat of copper is 0.385 J/g °C.

Polar covalent bonds are formed when the electrons in the bond are not shared equally between the two nuclei. which one of these molecules contains polar bonds?