Do elements in the same group have same principle number?

If the density of water is 1.0 g/cm3, which of these materials would float in water, based on their densities? check all that apply. aluminum cork iron lead wax

The standard emf for the cell using the overall cell reaction below is +2.20 v: 2al(s) + 3i2(s) → 2ai3+(aq) + 6i-(aq) the emf generated by the cell when [ai3+] = 3.5 × 10-3 m and [i-] = 0.015 m is v. the standard emf for the cell using the overall cell reaction below is +2.20 v: 2al(s) + 3i2(s) 2ai3+(aq) + 6i-(aq) the emf generated by the cell when [ai3+] = 3.5 × 10-3 m and [i-] = 0.015 m is v. 2.36 2.24 2.21 2.51 2.04

Amole, which is a unit in chemistry, contains 6.02 x 1023 atoms or particles. how many zeroes follow the 2 when this number is written out in standard form? a) 21 b) 23 c) 24 d) 25