Answer:
C.Echinoderms have radial symmetry and worms have bilateral symmetry
Explanation:
Echinoderms evolved from animals with bilateral symmetry. The larvae of all echinoderms are bilaterally symmetrical but lost during metamorphosis developing into radial symmetry adult. Examples of echinoderms are starfish, sea urchins, sand dollars.
Worms are invertebrate animals having bilateral symmetry. They have a definite anterior (head) end and a posterior (tail) end. Worms have brains that help them detect objects, food, mates, and predators quickly.
Answer:
Explanation:
a) The forward reaction is exothermic, hence when temperature is increased the equilibrium shift towards the reactants side to get rid of the excess energy. This will mean that more reactants are produced decreasing yield
b) There are a fewer number of moles of gas on the right side compared to the left side (Just count the coefficients before each compound) so a higher pressure will mean that the equilibrium will shift towards the products side in order to decrease the pressure. This will mean that more products are formed increasing yield
c) When something is powdered it's surface area to volume ratio increases. A higher surface area means that the particles around it have more area to work on so the frequency of collisions will increase increasing the rate of reaction. This is why iron is powdered.
The method of determining the most common isotope of lead is by determining the average atomic mass. The formula for determining the average atomic mass is:
Substituting the values in the formula:
The most common isotope of lead is:
Lead - 207.22 amu
The atomic symbol of lead is 
. The atomic number of is 82.
So, the the most common isotope of lead can be written as:
and Lead - 207.22 amu.
Answer:
gram
Explanation:
Gram is a SI unit (International Ststem of units)
other SI units : kg , meter, ampere, Kelvin
pound gallon and foot are SAE (or imperial) units
Answer:
4.3 x 10⁶ kJ are released
Explanation:
From the balanced chemical equation we know that when 2 moles of hydrogen peroxide decompose, 191 kJ of heat are released. So what we need to calculate is the number of moles the 765 kg of H2O2 represent and calculate the heat released.
Molar Mass H2O2 = 34.01 g/mol
Mass H2O2 = 765 Kg x 1000 g/Kg = 765000 g
moles H2O2 = 1 Mol / 34.01 g x 765000 grams = 22.5 Mol
(-196.1 kJ/ 2 mol H2O2 ) x 22.5 mol H2O2 = -4.3 x 10⁶ kJ
