Answer:
26.981539 u
Explanation:
One mole of Al atoms has a mass in grams that is numerically equivalent to the atomic mass of aluminum. The periodic table shows that the atomic mass (rounded to two decimal points) of Al is 26.98, so 1 mol of Al atoms has a mass of 26.98 g.
When a substance absorbs thermal energy, it partitions some as potential and some as kinetic energy. Specific heat is an expression related to the quantity of heat a substance stores as potential energy; the remainder is absorbed as kinetic which causes the temperature to increase - recall that temperature is a measure of average kinetic energy.
When specific heat is low, most of the energy is partitioned as kinetic energy and the substance will experience the greatest temperature change.
So rather than calculating the change in temperature, we can simply inspect the specific heats. The one with the lowest will experience the greatest temperature change. We could also compare the specific heats: Al = .897/.385 ==> 2.3, Fe = .452/.385 = 1.2, Cu = .385/.385 = 1. We can expect Copper's temperature change to be 2.3 times larger than Aluminum's and 1.2 times larger than Iron's.
Answer:
homologous structures.
Explanation:
If you look at many different organisms, you will see similar structures. Like humans have a forearm, birds have a wing, whales have fins, leopards have legs. The bones evolvolved to fit the animal
Answer:
The correct answer is: 6.6 g MgO
Explanation:
First we have to write and balance the chemical reaction as follows:
2Mg(s) + O₂(g) → 2MgO(s)
That means that 2 moles of Mg(s) react with 1 mol of O₂(g) to give 2 moles of MgO(s). If Mg is totally consumed and a mass of O₂ remains unaltered after reaction, t<em>he limiting reactant is Mg</em>. We use the limiting reactant to calculate the mass of product.
According to the balanced chemical equation, 2 moles of Mg(s) produce 2 moles of MgO(s).
2 moles Mg = 2 mol x molar mas Mg= 2 mol x 24.3 g/mol = 48.6 g Mg
2 moles MgO= 2 mol x (molar mass Mg + molar mass O) = 2 mol x (24.3 g/mol + 16 g/mol) = 80.6 g MgO
The stoichiometric ratio is 80.6 g MgO/48.6 g Mg. So, we multiply this ratio by the mass of consumed Mg (4.0 g) in order to obtain the produced mass of MgO:
4.0 g Mg x 80.6 g MgO/48.6 g Mg = 6.63 g MgO
6.6 grams of magnesium oxide are formed.
Answer:
I believe the answer is A. it could be A or D. But I trust A. sorry if i'm wrong
