Answer:
19.32
Explanation:
the density is given by the mass over volume
the mass In this case is 342.93 and the volume is 17.75
d=342.93g/17.75cm
=19.32g/cm
i hope this helps
Molar mass Na = 23.0 g/mol
1 mol ---- 23.0 g
n mol ---- 69 g
n = 69 / 23.0
n = 3.0 moles
1 mole -------- 6.02x10²³ molecules
3.0 moles ---- ?
3.0 * 6.02x10²³ / 1
= 1.806x10²⁴ molecules
hope this helps!
Yes, this is balanced. Each part of the substance (like Mg) has the same number on both sides.
Hope this helps you:)