Answer:
5 mph
Explanation:
100 miles, 20 hours (divide by 2)
50 miles, 10 hours (divide by 2)
25 miles, 5 hours (divide by 2)
divide both sides by 5
5 miles, 1 hour
*A & B*
Answers A & B are not possible, as Hydrogen “bonds” are intermolecular forces and do not actually involve transfer or sharing of electrons.
*C & D*
Viscosity and surface tension are not the answer as they are not specific enough to the question.
*E*
Polarity of water molecules is the correct answer, as water molecules are highly polar. The partial positive of the Hydrogen on one water molecule is highly attracted to the partial negative of the Oxygen (due to its lone pairs) on another water molecule.
Answer:
2Mg + O₂ ⟶ 2MgO
Explanation:
Step 1. Start with the most complicated-looking formula (O₂?).
Put a 1 in front of it.
Mg + 1O₂ ⟶ MgO
Step 2. Balance O.
We have fixed 2 O on the left. We need 2O on the right. Put a 2 in front of MgO.
Mg + 1O₂ ⟶ 2MgO
Step 3. Balance Mg.
We have fixed 2 Mg on the right-hand side. We need 2 Mg atoms on the left. Put a 2 in front of Mg.
2Mg + 1O₂ ⟶ 2MgO
Every formula now has a coefficient. The equation should be balanced. Let’s check.
<u>Atom</u> <u>On the left</u> <u>On the righ</u>t
Mg 2 2
O 2 2
All atoms are balanced.
The balanced equation is
2Mg + O₂ ⟶ 2MgO
To work out the kinetic energy of an object, you use the formula:
E = 0.5 x (mass) x (velocity)^2
One important thing, though. The units MUST be consistent. Mass needs to be in kilograms, and velocity in metres per second.
To convert the mass form grams to kilograms, we need to divide it by 1000, getting 0.0103 kg. Since the velocity is already in the units we need, we can just plug the numbers into the equation to get:
E = 0.5 x (0.0103 kg) x (48.0)^2 = 11.8656 J = 11.9 J, to 3 significant figures
Hope I helped! xx
