Answer: oxygen
There is the s,p,d and f blocks, from groups 1-2 that is the s block, 13-18 that’s the p block, 3-12 is the d block and the f would be lanthanide(#57-71) and actinide (#89-103).
Sedimentary rocks. Not sure though
Answer:
See explanation
Explanation:
Electron affinity is the energy released when an extra electron is added to a neutral gaseous atom. A negative value of electron affinity indicates that energy is given out and vice versa.
Metals have positive electron affinity since electrons rarely accept electrons, so;
Na(g)+ 1e^- → Na^-(g) positive
Mg(g)+1e^- → Mg^-(g) positive
For the last case; Br(g)+ 1e^- → Br^-(g), the electron affinity for the non-metals is negative. hence the answer
After that have been up for a while thay are metal
