Answer:
A is the closest thing. You change the composition of the steak. You don't in any of the others.
Explanation:
Usually when you cook something, you are doing something to the composition of the object being cooked. A steak might not be obvious, but boiling an egg should be.
Chopping a tree is something physical. You are removing mass in such a way that the tree will fall. There's nothing chemical about that.
Heating a cup of tea looks like it might be chemical. After all steam is sometimes given off which looks like it is chemical. It's not. The water in the tea is just changing phase.
Drying clothes in a dryer. Again, this looks like something might have changed. After all the mass of the clothes just became less. But all you are doing is separating two masses (leaving one of them behind).
Molarity refers to moles/ L. This indicates the concentration of a solution containing solute and solvent.
1 molar solution contains 1 mole of solute in 1 L of solvent.
According to Avogadro's number, 1 mole of a substance contains 6.023 x 10^23 molecules, atoms, or ions.
For this reason, 6.023 x 10^23 atoms, ions, or molecules are in a molar solution.
____NaNO3 + ___PbO --> ___Pb(NO3)2 + ___Na[2]O
To balace the eqaution, you need to have the same number of atoms for each element on both the reactant (left) and product (right) side.
To start off, you wanna know the number of atoms in each element on both sides, so take it apart:
[reactants] [product]
Na- 1 Na- 2
N- 1 N- 2(it's 2 because the the subscript [2] is outside of the parenthesis)
O- 4 O- 7 (same reason as above)
Pb- 1 Pb- 1
Na is not balanced out, so add a coefficient to make it the same on both sides.In this case, multiply by 2:
2NaNO3
Now Na is balanced, but the N and O are also effected by this, so they also have to be multiplied by 2 and they become:
Na- 2 Na- 2
N- 2 N- 2 (it balanced out)
O- 7 (coefficient times subscript, plus lone O) O- 7 (balanced out)
Pb was already balanced so no need to mess with it, just put a 1 where needed (it doesn't change anything).
Now to put it back together, it will look like this:
2NaNO3 + 1PbO --> 1Pb(NO3)2 + 1Na[2]O
Answer:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
Explanation:
H₂²⁺(aq) + O₂²⁻(aq) + Mg²⁺(aq) + SO₃²⁻(aq) → Mg²⁺(aq) + SO²⁻₄(aq) + H₂O(l)
A careful observation of the equation above, shows that the equation is already balanced.
To obtain the net ionic equation, we simply cancel Mg²⁺ from both side of the equation as shown below:
H₂²⁺(aq) + O₂²⁻(aq) + SO₃²⁻(aq) → SO²⁻₄(aq) + H₂O(l)
Answer:
Movement in narrow zones along plate boundaries causes most earthquakes. Most seismic activity occurs at three types of plate boundaries—divergent, convergent, and transform. As the plates move past each other, they sometimes get caught and pressure builds up.
Explanation:
