how long was all the matter in the universe theorized to be compressed into a minuscule scalding mass?

Is the group number the number of electrons on the outermost shell

Hydrogen has 3 isotopes 1 H 2 H and 3 H. What is the difference between these 3 isotopes

What is the Molarity of 0.60 moles of solute in 0.40 L of solution?

What do alkali metals do with that one electron

Calculate the equilibrium constant at 25 ∘C for the reaction Fe (s) + 2Ag + (aq) →Fe2 + (aq) + 2Ag (s) Standard Reduction Potentials at 25 ∘C Fe2 + (aq) + 2e-→Fe (s) E∘ = - 0.45 V Ag + (aq) + e-→Ag (s) E∘ = 0.80 V

Identify the number of core and valence electrons for each atom. Xe : core electrons Xe : valence electrons Ca : core electrons Ca : valence electrons Br : core electrons Br : valence electrons

What do the lines around the finger of the doorknob represent?

Identify what type of reaction is below. Also determine what coefficients that would balance the chemical equation.

Much of life on Earth is based in aquatic biomes. What property of water allows life to survive in liquid water?

A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have? 13 9 5 4