Answer:
The atomic mass (mₐ or m) is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit atomic mass unit (AMU) or unified mass (u) or dalton (symbol: Da), where 1 AMU or 1 u or 1 Da is defined as 1⁄12 of the mass of a single carbon-12 atom, at rest. The protons and neutrons of the nucleus account for nearly all of the total mass of atoms, with the electrons and nuclear binding energy making minor contributions.
Mass percentage = (mass of Al)/(Total mass) * 100
= (26.98) / (26.98 + 3 * (1.0079 + 16)) * 100
= 34.59%
Answer: Transition metal
Explanation: Copper is definitely a transition metal because the Cu2+ ion has an incomplete d level.
S orbital can hold 2
P can hold 6
D can hold 10
F can hold 14
12 pens for writing chemical formulas cost
12*2=24 dollars
12 pads cost
12*3=36 dollars
1)
12*2=24
12*3=36
2)
12*2+12*3=60 dollars
3) 12*(3+5)=60 dollars
