<span>1. In any nuclear reaction, nuclei are transformed in some way.
True
2. Two fissionable substances commonly used in nuclear reactors and nuclear weapons include uranium-235 and plutonium-239.
True
3. Fission reactions can be controlled; thus, they are used to create energy and electricity. But fusion reactions are uncontrollable and require too much energy for economical use.
True
4. Fission reactions occur at such high temperatures in the Sun that the Sun appears to glow.
False
Hope this answers the question. Have a nice day.</span>
<h3>
Answer:</h3>
8.09 × 10²² formula units
<h3>
Explanation:</h3>
Mass of MgCl₂ is 12.8 g
Required to calculate the formula units
1 mole of a compound contains the Avogadro's number formula units
That is;
1 mole = 6.022 × 10²³ formula units
<h3>
Step 1: Calculate the moles of MgCl₂ in 12.8 g </h3>
The molar mass of MgCl₂ is 95.211 g/mol
Number of moles = Mass ÷ molar mass
Moles of MgCl₂ = 12.8 g ÷ 95.211 g/mol
= 0.1344 mole
<h3>Step 2: Calculate the formula units of MgCl₂</h3>
1 mole = 6.022 × 10²³ formula units
Therefore;
Number of formula units = Moles × 6.022 × 10²³ formula units
= 0.1344 mole × 6.022 × 10²³ formula units
= 8.09 × 10²² formula units
Therefore, there are 8.09 × 10²² formula units in 12.8 g of MgCl₂
In the atom model, the poppy seeds are placed in different places to represent the different position of electrons.
