How many neutrons does an element have if its atomic number is 40 and its mass number is 154

Consider a solution that is 2.0*10-2 M in Fe2 + and 1.8*10-2 M in Mg2+. (Ksp for FeCO3 is 3.07*10-11 and Ksp for MgCO3 is 6.82*10-6.

A newly discovered element, Y, has two naturally occurring isotopes. 90.3 percent of the sample is an isotope with a mass of 267.8 u, and 9.7 percent of the sample is an isotope with a mass of 270.9 u.

Explain why living organisims contain more hydrogen atoms then any other atoms, yet 65% of typical organisims mass is oxygen

Calculate q, w, ΔE, and ΔH, when 175 g of water evaporates at 1.00 atm and 100.0 °C. The heat of vaporization of water is 40.7 kJ/mol. q = kJ w = kJ ΔE = kJ ΔH = kJ

Suppose your laboratory partner tells you the density of water at 20 celsius is 0.99910 g/cm (cubic). Is this a reasonable number? Why or why not?

The 1s orbital (s) do (es) not have any nodes. the 1s orbital (s) has (have) a node at the nucleus. the 3d orbital (s) has (have) a cloverleaf shape, with four lobes of electron density around the nucleus and two perpendicular nodal planes.

The least electronegative element from among the following is A. Na. B. Cl. C. Cs. D. S.

Which description explains how inertia changes the effects of gravity on objects in the solar system?

Real-life example of an exponential decay.

What is the molarity of an acid that is made up of 9.5 moles of HCl dissolved in 1:24 L of water?