Answer:

Explanation:
You can calculate the entropy change of a reaction by using the standard molar entropies of reactants and products.
The formula is

The equation for the reaction is
C₂H₄(g) + 3O₂(g) ⟶ 2CO₂(g) + 2H₂O(ℓ)
ΔS°/J·K⁻¹mol⁻¹ 219.5 205.0 213.6 69.9

I’m positive it’s gonna be c
The volume of a 1.86-carat diamond in cubic centimeters is 0.106 cm³
Given,
The density of a diamond is 3.513 g/cm³.
We have to find out the volume of a 1.86-carat diamond in cubic centimeters.
Convert the units of the diamond from carat to grams, we have:
(1.86 carats) x (0.200 g / 1 carat) = 0.372 g
The volume of the diamond is obtained by dividing the mass by the density, therefore using the formula, we get
v = m / d
v = 0.372 g / (3.51 g/cm³) = 0.1059 cm³
or, v = 0.106 cm³ (approx)
Therefore, the volume of a 1.86-carat diamond is approximately 0.106 cm³.
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LiBr.
<h3>Explanation</h3>
Note that the group number in this answer refers to the new IUPAC group number, which ranges from 1 to 18. Counts from the left. Start with the first two column (group 1 and 2), go on to the transition elements (Sc, Ti, etc. in group 3 through 12), and continue with the nonmetals (group 13 through 18).
Li is a group 1 metal. As a metal, it tends to form positive ions ("cations"). Metals in group 1 and 2 are <em>main group</em> metals. The charge on main group metal ions tends to be the same as the group number of the metal. Li is in group 1. The charge on an Li ion will be +1. Formula of the Li ion will be
.
Br is a group 17 nonmetal. As a nonmetal, it tends to form negative ions ("anions"). The charge on nonmetal ions excepting for H tends to equal the group number of the nonmetal minus 18. Br is in group 17. The charge on a Br ion will be 17 - 18 = -1. Formula of the Br ion will be 
All the ions in an ionic compound carry charge. However, some of the ions like
are positive. Others ions like
are negative. Charge on the two types of ions balance each other. As a result, the compound is <em>overall</em> neutral.
1 × (+1) + 1 × (-1) = 0. The positive charge on one
ion balances the negative charge on one
ion. The two ions would pair up at a 1:1 ratio.
The empirical formula for an ionic compound shows all the ions in the compound. Positive ions are written in front of negative ions.
is positive and
is negative. The formula shall also show the simplest ratio between the ions. For the compound between Li and Br, a 1:1 ratio will be the simplest. The "1" subscript in an empirical formula can be omitted. Hence the formula: LiBr.
Answer:
Fossils tell us when organisms lived, as well as provide evidence for the Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils, by comparing the anatomies of both modern and extinct species, allows scientists to study the skin, hair, and organs of ancient creatures.
Explanation: