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.)
The most common compound on earth is cellulose because it has enough energy to be the next source for biofuels.
A beta particle is an electron and it has a -1 charge and zero mass.
Beta decay by
emitting an electron is called as β⁻
decay. When this happens, a neutron of the element converts into a proton by
emitting an electron. Hence, the mass of daughter nucleus is same as parent
atom but atomic number/number of protons is higher by 1 than atomic number of
parent atom.
In a β⁻ decay, the symbol is used as ₋₁⁰β or ₋₁⁰e.
-1 is for charge
<span> 0 is for the mass of the particle
</span>