Answer:
H2O
Explanation:
hydrogen has 1 electron
and oxygen has 6 electron which form a water molecule Atom
It seems like the answer is C, you really just need to use the process of elimination.
The answer is b i just took the quiz and got it right|| k12.gca student
Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶


Density of iron bar

= 7870 kg/m³ (3 s.f.)
7.

Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³

Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume

(3 s.f.)
n = m / M
Where, n is moles of the compound (mol), m is the mass of the compound (g) and M is the molar mass of the compound (g/mol)
Here, the given ethanol mass = 50.0 kg = 50.0 x 10³ g
Molar mass of the ethanol = (12 x 2 + 1x 6 + 1 x 16) g/mol
= 46 g/mol
Hence, moles in 50.0kg of ethanol = 50.0 x 10³ g / 46 g/mol
= 1086.96 mol