<span>3.2 grams
The first thing to do is calculate how many half lives have expired. So take the time of 72 seconds and divide by the length of a half life which is 38 seconds. So
72 / 38 = 1.894736842
So we're over 1 half life, but not quite 2 half lives. So you'll have something less than 12/2 = 6 grams, but more than 12/4 = 3 grams.
The exact answer is done by dividing 12 by 2 raised to the power of 1.8947. So let's calculate 2^1.8947 power
= 12 g / (e ^ ln(2)*1.8947)
= 12 g / (e ^ 0.693147181 * 1.8947)
= 12 g / (e ^ 1.313305964)
= 12 g / 3.718446464
= 3.227154167 g
So rounded to 2 significant figures gives 3.2 grams.</span>
Answer:
» An electron is lighter than a proton.
<u>explanation</u><u>:</u>

hence it's mass number is zero

hence it's mass number is 4
<u>Therefore</u><u>,</u><u> </u><u>proton</u><u> </u><u>is</u><u> </u><u>heavier</u><u> </u><u>than</u><u> </u><u>electron</u>
» An electron has a small charge magnitude than a proton.
<u>Explanation</u><u>:</u>
An electron has charge of -1 while proton has charge of +2, therefore electron is less deflected by any energetic fields than a proton
Answer:
b)determining the electric field due to each charge and adding them together as vectors.
Explanation:
The electric Field is a vector quantity, in other words it has a magnitude and a direction. On the other hand, the electric field follows the law of superposition. The electric field produced by two elements is equal to the sum of the electric fields produced by each element when the other element is not present. in other words, the total electric field is solved determining the electric field due to each charge and adding them together as vectors.
Answer: When the flashlight is turned on, the chemical energy stored in batteries is converted into electrical energy that flows through wires of flashlight. This electrical energy is then transformed into light and heat energies.
Explanation: