The characteristic that helium has that distinguishes it from the noble gases would be that it only has 2 valence electrons while noble gases has a completely filled orbitals giving it 8 valence electrons and a stable electron configuration. The valence electrons is the number of electrons that is present in an atom that can take part in the formation of bonds. These electrons can be found on the outermost shell of an atom. Helium is an exception to the octet rule, its atom has only two available electrons in its outermost shell since it only has one eletron shell that is the only the s orbital which can hold two electrons only.
Amylase is the enzyme found in saliva an starts to digest food from in the mouth. Starch is a polysaccharide found in foods such as bread, yam, potatoes. This molecule is the carbohydrate component of foods and is the main source of energy as food. At the moloecular level, the enzyme amylase breaks the bond that forms maltose into two individual glucose molecules.
Answer:
6 C O 2 + 6 H 2 O + Δ → C 6 H 12 O 6 + 6 O 2
Explanation:
The Δ symbol denotes added energy, here in the form of sunlight. Strong C = O , and O − H bonds have been broken, and this bond cleavage is only partially energetically compensated by the formation of C − H and O = O bonds. Hence the reaction is endothermic (energy input on LHS). Note that the reaction is balanced with respect to mass and charge (says he, checking to see whether it is indeed balanced!).
Answer:
D. Al(s) + O₂(g) → Al₂O₃(s)
Explanation:
Aluminum is a solid metal, so it is written as Al(s).
Oxygen is a diatomic gas, so we write this compound as O₂(g).
Aluminum oxide has the formula Al₂O₃ because in oxides the oxidation number of oxygen atom is -2 and for aluminum, the oxidation number is 3. Thus, we write this compound as Al₂O₃(s).
Now, we have to found the chemical equation in which the reactants (left side) are Al(s) and O₂(g) while the product (right side) is Al₂O₃(s). From the options, we can see that the correct is (D):
Al(s) + O₂(g) → Al₂O₃(s)
It is true. Since it is very reactive with oxygen and water, it is kept in kerosene or some other some other oil