to which grop and period do the following elements belong carbon, neon, aluminium, potassium ,calcium, sulphur​

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?