Answer=B and D
Both are types of potential energy that involve stored energy.
- log (1.5 x 10^-3) = pOH = 2.824
<span>14 - 2.824 = pH = 11.176 </span>
<span>10 ^ (-11.176) = [H3O+] = 6.668 x 10^-12</span>
Answer:
4
Explanation:
The zeros before a non zero digit do not count as significant figures so there are 4 sig figs in the number
Answer:
% oxygen = 47.1 %
% aluminium = 52.9 %
Explanation:
Step 1: Data given
Mass of aluminium = 2.70 grams
Mass of aluminium oxide = 5.10 grams
Step 2: The balanced equation
4Al + 3O2 →2Al2O3
Step 3: Calculate mass of oxygen
The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products.
Mass oxygen + mass aluminium = mass aluminium oxide
Mass oxygen + 2.70 grams = 5.10 grams
Mass oxygen = 5.10 grams - 2.70 grams
Mass oxygen = 2.40 grams
Step 4: Calculate percent composition
% oxygen = (mass oxygen / mass aluminium oxide) * 100 %
% oxygen = (2.40 grams / 5.10 grams ) * 100 %
% oxygen = 47.1 %
% aluminium = (mass aluminium / mass aluminium oxide)
% aluminium = (2.70 grams / 5.10 grams ) * 100 %
% aluminium = 52.9 %
47.1 % + 52.9 % = 100 %
Frequency = speed of light/ wavelength of photon. wavelength = speed of light/frequency = 3 x 10^8 / 2.43 x 10^8= 1.23m