Which elements forms an ion with a 1– charge?

Nickel crystallizes in the face-centered cubic (fcc) lattice. the density of the metal is 8902 kg/m3. calculate the radius of a nickel atom.

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

What’s the scientific notation for the number 6,840,000,000