<span>A SI base unit is the single and direct measurement unit for a physical entity. E.g. For mass it is kg, for time it is sec, A derived unit is determined by a physical equation with the base units, like for velocity equals distance divided by time, in SI units: unit of v (velocity)= m (meter) divided by sec (seconds).
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Answer:
A. car moving down the highway
Explanation:
Potential energy is when the energy is being held in, as in, it is very still, and not moving.
When a car is moving down a highway, it is releasing kinetic energy, instead of potential.
Answer :
According to the law of conservation of mass, the mass of reactants must be equal to the mass of products.
The balanced chemical reaction is,

As we know that the molar mass of magnesium is 24 g/mole, the molar mass of
is 32 g/mole and the molar mass of magnesium oxide is 40 g/mole.
From the given balanced reaction, we conclude that
As, 1 mole of magnesium react
mole of oxygen to give 1 mole of magnesium oxide.
So, the mass of Mg is 24 g, the mass of
and the mass of MgO is 40 g.
That means 24 g of Mg react with 16 g
to give 40 g of MgO.
In this kind of exercises, you should use the "ideal gas" rules: PV = nRT
P should be in Pascal:
445mmHg = 59328Pa
1225mmHg = 163319Pa
V should be in cubic meter:
16L = 0.016 m3
R =

= constant

=

==> P1 * V1 = P2 * V2
V2 =

=
V2 = 0.00581 m3 = 5.81 L
Answer:
0.60 moles of Na₂SO₄
Explanation:
Molarity is an unit of concentration defined as the ratio between moles of solute and liters of solution.
A solution of Na₂SO₄ 0.40M contains 0.40 moles of solute (Na₂SO₄) per liter of solution.
As you have 1.5L of solution, moles of Na₂SO₄:
1.5L × (0.40mol / L) = <em>0.60 moles of Na₂SO₄</em>