Answer:
A. When an anhydrous salt becomes hydrated, it can change color.
Explanation:
The cobalt (II) chloride (CoCl₂) have a blue color in the anhydrous form while after hydration, most commonly it will form the hexahydrate, it will change its color to violet.
B. not really, if we take the cobalt (II) chloride in the anhydrous form the bond between cobalt and the chloride it is ionic.
C. nope, the mass is changed depending on the lost water mass
D. no, the mass will increase and sometimes as in the case of cobalt (II) chloride the color will change, so you have changes of the physical properties of the substance.
I think it would be:
Is the author stating fact or opinion?
Does the author have evidence for the given facts?
Maybe
How many article has the author written before?
Ones you add if you wanted to is
Does the author give any sources? (Like where they got the info)
Answer:
Two electrons
Explanation:
According to the octet rule, atoms must bond to each other, sharing electrons among themselves in an attempt to complete their valence shell (last layer of the electrosphere). In other words, an atom becomes stable when it has 8 electrons in its valence shell.
Oxygen atoms have six electrons in their valence shell, so to achieve the stability suggested by the octet rule (eight electrons), these atoms share two electrons, forming one oxygen gas (O₂) molecule.
Answer:
In fact, the periodic table is so accurate that it allows scientists to predict the chemical and physical properties of elements that hadn't yet been discovered. ... "The elements, if arranged according to their atomic weights, exhibit an apparent periodicity of properties," said Mendeleev.
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.
