Zinc is an example of a pure metal with a hexagonal close-packed arrangement.
~Glad to help ^^
If you look at the periodic table you’ll noticed a trend. Group one, sometimes called 1A, has hydrogen in it, it’s group (column) has a positive charge. The group (column) next to it Group 2 sometimes called 2A has twice the charge as group 1. Then you skip the transition metals, and then land on group (column) 13. These guys have a charge of +3 typically. Then you have group 14, sometimes called 4A, and it’s weird and it kind of breaks with this trend. Then you have group (column) 15 next to it, sometime called 5A, which now starts to count down in charge, it has a charge of -3.
And each group (column) after that countdown to zero charge, once you have zero charge you know that you’re in the noble gases.
So, nitrogen in group (column) 15, also know as column 5A. This column has for the most part a charge of -3.
Aluminum is in group (column) 13, they have a charge of +3 typically.
I hope that helps.
Answer:
1. d. The reaction is spontaneous in the reverse direction at all temperatures.
2. c. The reaction is spontaneous at low temperatures.
Explanation:
The spontaneity of a reaction is associated with the Gibbs free energy (ΔG). When ΔG < 0, the reaction is spontaneous. When ΔG > 0, the reaction is non-spontaneous. ΔG is related to the enthalpy (ΔH) and the entropy (ΔS) through the following expression:
ΔG = ΔH - T. ΔS [1]
where,
T is the absolute temperature (T is always positive)
<em>1. What can be said about an Endothermic reaction with a negative entropy change?</em>
If the reaction is endothermic, ΔH > 0. Let's consider ΔS < 0. According to eq. [1], ΔG is always positive. The reaction is not spontaneous in the forward direction at any temperature. This means that the reaction is spontaneous in the reverse direction at all temperatures.
<em>2. What can be said about an Exothermic reaction with a negative entropy change?</em>
If the reaction is exothermic, ΔH < 0. Let's consider ΔS < 0. According to eq. [1], ΔG will be negative when |ΔH| > |T.ΔS|, that is, at low temperatures.
Answer:
There are a number of possibilities for the answer to this question, so I will address a few only:
Explanation:
1. Many ionic substances will dissolve completely in water to form an aqueous solution of cations and anions; this solution will conduct electricity.
2. The substance will have a slightly lower melting point than a mid-level covalent network solid.
3. The substance will certainly not conduct electricity as a solid.
Answer:
18 is a
19 is c
20 i am not sure
Explanation:
18)nucleus contains protons and neutrons
