Chemical changes are irreversible.
A chemical change that could happen at school would be when you have a chemistry experiment and you mix an acid and a base such as mixing hydrochloric acid with sodium hydroxide.
A chemical change that could happen at home would be baking a cake. You can't take the ingredients used in baking a cake back apart because they have changed their chemical composition.
A chemical change that happens in nature could be a forest fire. The burning of wood would be the chemical change in this case.
Answer:
The answer is D. The Sun is the closest star to Earth and so it seems brighter than distant stars that have much greater absolute brightness.
Explanation: Stars like red super giants like beetleguise are way brighter and bigger than the sun, but the sun is closest to the earth. It is only in its main sequence stage but seems bright because of its short distance from the sun( 93 million miles).
Answer:
0.8162 gramos de plomo por gramo de yodo
1.633 gramos de plomo por gramo de yodo
Explanation:
Asumiendo una base de 100 gramos para cada compuesto:
Primer compuesto:
Gramos plomo: 44.94g
Gramos de yodo: 100-44.94g = 55.06g
Así, la masa de plomo por gramos de yodo para el primer compuesto es:
44.94g plomo / 55.06g Yodo =
<em>0.8162 gramos de plomo por gramo de yodo</em>
<em></em>
Segundo compuesto:
Gramos plomo: 62.02g
Gramos de yodo: 100-62.02g = 37.98g
La masa de plomo por gramos de yodo para el segundo compuesto es:
62.02g plomo / 37.98g Yodo =
<em>1.633 gramos de plomo por gramo de yodo</em>
