Answer: Read Explanation
Explanation: Index fossils are useful because they tell the relative ages of the rock layers in which they occur. Geologists use particular types of organisms, such as trilobites, as index fossils.
Answer:
The final balanced equation is
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
Explanation:
It is given that sodium hydroxide is added to collect the solid nickel(II) hydroxide product
The empirical equation for this statement is
Ni2+ + NaOH --> Ni (OH)2 + Na+
We will first balance the hydroxide molecule. On the right side there are two OH molecules.
Thus, on the left side we will take 2 sodium hydroxide
Ni2+ + 2NaOH --> Ni (OH)2 + Na+
Now we will balance the sodium ion which are 2 in numbers on the left side and 1 on the right side
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
So, the final balanced equation is
Ni2+ + 2NaOH --> Ni (OH)2 + 2Na+
Answer:
Oxygen
Explanation:
because oxygen is used when making and sustaining a fire.
I think this seems like something is missing from the question