A heterogeneous mixture composes of non- uniform components, so the concrete would be the answer, because you can tell the components from one another.
They can all travel through empty space
The correct answer is D,
dose this help?
Answer:
Group 17 Melting point 113.7°C, 236.7°F, 386.9 K
Period 5 Boiling point 184.4°C, 363.9°F, 457.6 K
Block p Density (g cm−3) 4.933
Atomic number 53 Relative atomic mass 126.904
State at 20°C Solid Key isotopes 127I
Electron configuration [Kr] 4d105s25p5 CAS number 7553-56-2
Explanation: