A mirror is opaque, meaning that it reflects the light and images that shine on it's reflective surface.
Answer:
C, A, A, B, B
Explanation:
Question 5: C. continental drift
Question 6: A. new rock forms
Question 7: A. happens at deep-ocean trenches
Question 8: B. convection currents in the mantle
Question 9: B. convergent boundary
<span>2.70x10^7 pm^3
We will assume that the sodium atom closely approximates a sphere. So the expression for the volume of a sphere is
V = 4/3 pi r^3
V = 4/3 pi (186 pm)^3
V = 4/3 pi 6434856 pm^3
V = 26954261.78 pm^3
Round to 3 significant figures, giving 2.70x10^7 pm^3</span>
Answer:
to balance a chemical equation the amount of reactants must be equal to the amount of products, an easy way to balance it is write out how many you have on both sides
Explanation:
if you're dealing with molecular equations you would do it like this:
eg. A double displacement reaction between magnesium hydroxide and hydrochloric acid
Mg(OH)2 (aq) + HCl (aq) = MgCl2 (aq) + H2O (l)
Mg-1. Mg-1
O-2. O-1 *2
H-2. H-2
Cl-1 *2 Cl-2
Balanced eq: Mg(OH)2 (aq) + 2HCl (aq) = MgCl2 (aq) + 2H2O (l)
if you're dealing with ionic equations , you would deal with charges and you would need to cancel out spectator ions, like this:
Mg^2+(aq) + 2OH^-(aq) + 2H^+ (aq) + 2Cl^- (aq) = Mg ^2+(aq)+ 2Cl^- (aq) + H20 (l)
the spectator ions are the ones that are the same on both sides which would be the Mg^2+ and the 2Cl^- so when writing the net ionic equation, it would just be:
2OH^-(aq) + 2H^+ (aq) = + H20 (l)
The amount of chemical energy a substance has is influenced by its structure and the bond the substance has.
Some bond is release energy when broken, other bond need some energy to break. The structure will also influence the chemical energy.
One of substance with high chemical energy is adenosine triphosphate which was used as energy source in a living organism. The phosphate bond in this molecule worth about 30.5 kJ/moles