Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
Answer:
D. ionic sodium phosphate (Na3PO4)
Explanation:
Answer:
I believe the answer to be period 3 group 1
Redox
reactions are those in which the oxidation numbers of the elements involved are
changed.
Equation
1:
2Na(s)
+ Cl2(g) --> 2NaCl
The
oxidation numbers of Na and Cl in the reactant side are both zero because they
are in elemental form. In the product side, however, the oxidation numbers are
+1 and -1, respectively. Hence, this is an example of redox reaction.
Equation
2:
Cd(s)
+ Pb+2(aq) --> Cd2+(aq) + Pb(s)
The
oxidation numbers of Cd and Pb+2 in the reactant side are 0 and +2,
respectively. They are, however, +2 and 0 in the product side. Hence, this is
also a redox reaction.
Equation
3:
Pb(NO3)2(liq)
+ 2LiCl(aq) --> PbCl2(s) + 2LiNO3(aq)
The
oxidation numbers of the involved ions (both cations and anions) are not
changed. Hence, this is NOT an oxidation reaction.
Equation
4:
C(s)
+ O2(g) --> CO2(g)
Just
as the equation 1 and 2, the oxidation numbers of the reactants are not similar
to those in the product. Hence, this is an example of oxidation reaction.
Answer:
27.7 grams of Li
0.140 moles of Co
0.158 moles of K
59.9 grams of As
8.00x10⁻⁹ moles of U
142.8 moles of H
0.0199 moles of O
0.666 moles of Pb
Explanation:
Mass / Molar mass = Mol
Mol . Molar mass = Mass
3.99 m . 6.94 g/m = 27.7 grams of Li
8.28 g / 58.93 g/m = 0.140 moles of Co
6.17 g / 39.1 g/m = 0.158 moles of K
0.8 mol . 74.92 g/m = 59.9 grams of As
6.02x10²³ (NA) particles are contained in 1 mol
6.02x10²³ are contained in 1 mol U____ 1 mol H ____ 1 mol O ___ 1 mol Pb
4.82x10¹⁵ atoms U ____ 4.82x10¹⁵/ 6.02x10²³ = 8.00x10⁻⁹ moles of U
8.60x10²⁵atoms H ____ 8.60x10²⁵ / 6.02x10²³ = 142.8 moles of H
1.20x10²² atoms O ____ 1.20x10²² / 6.02x10²³ = 0.0199 moles of O
4.01x10²³ atoms Pb ____ 4.01x10²³ / 6.02x10²³ = 0.666 moles of Pb
