Which electron configuration represents the electrons of an atom in an excited state?
(1) 2-1
(3) 2-8-7
(2) 2-7-4
(4) 2-4

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom

Answer asap need it by wednesday morning carry out the following calculations on ph and ka of from data. i. calculate the ph of 0.02m hcl ii. calculate the ph of 0.036m naoh iii. calculate the ph of 0.36m ca(oh)2 iv. calculate the ph of 0.16m ch3cooh which has ka = 1.74 x 10-5 mol dm-3 v. calculate ka for weak acid ha which has a ph of 3.65 at 0.30m concentration vi. calculate the ka of a solution made by mixing 15.0 cm3 0.2m ha and 60.0 cm3 0.31m a-. [ph= 3.80] vii. calculate the ph of a solution made by mixing 15.0 cm3 0.1m naoh and 35.0 cm3 0.2m hcooh. [ka = 1.82 x 10-4 m]

Atoms contain subatomic particles called protons and neutrons. when these protons and neutrons spilt, a lot of energy is released