Africa is the answer. Here is the packet, https://cms.springbranchisd.com/Portals/280/staff/robertsh1/exptra%20practice%20KEY.pdf?ver=2012-11-...
D = m / V
d = 5.0 / 45.0
d = 0.111 g/cm³
Energy would be the correct answer
1 elements
2 they have same number of valence electrons
3 period
