The elements in<span> groups 1a through 7a are called d. representative elements. The periodic table is organized according to increasing order of the atomic number of the elements. Groups have similar properties while the period of the elements determines the valence electrons in the outer shells.</span>
Answer:
a. +2
b. +3
c. -1
Explanation:
The typical oxidation states can be determined from the periodic table based on the number of valence electrons an atom has.
a. Calcium belongs to group 2A, meaning it has 2 valence electrons and, therefore, would have an oxidation state of +2 in compounds.
b. Aluminum is in group 3A, meaning it has 3 valence electrons and would have an oxidation state of +3 in compounds when the 3 electrons are lost.
c. Fluorine would become fluorine if it gained 1 additional electron to achieve an octet, so its oxidation state would be -1.
When equilibrium has been reached so, according to this formula we can get the specific heat of the unknown metal and from it, we can define the metal as each metal has its specific heat:
Mw*Cw*ΔTw = Mm*Cm*ΔTm
when
Mw → mass of water
Cw → specific heat of water
ΔTw → difference in temperature for water
Mm→ mass of metal
Cw→ specific heat of the metal
ΔTm → difference in temperature for metal
by substitution:
100g * 4.18 * (40-39.8) = 8.23 g * Cm * (50-40)
∴ Cm = 83.6 / 82.3 = 1.02 J/g.°C
when the Cm of the Magnesium ∴ the unknown metal is Mg
The Answer you are looking for is true
Answer:
Absorbed, endothermic
Explanation:
Based on the heat of reaction, chemical reactions may be classified as endothermic or exothermic.
In an endothermic reaction, heat is absorbed from the surrounding. As heat is absorbed from the surrounding, the reaction vessel feels cool when touched.
On the other hand, in an exothermic reaction, heat is given out by the system to the surrounding and the reaction vessel feels hot when touched.
Hence the reaction is endothermic and energy is absorbed during the reaction.
