Answer:
1.) Yes, Cs₂S
2.) Yes, MgF₂
3.) Yes, MgS
4.) No
Explanation:
Nonmetals are located on the right side of the periodic table in the p-block. It is safe to assume that all the other elements are metals.
Ionic bonds form between a metal and nonmetal. When determining the empirical formula, the cation (the element losing electrons) is written before the anion (the element gaining electrons). The charges can be balanced by modifying the quantity of element.
1.) Cs₂S
-----> Cesium = metal and Sulfur = nonmetal
-----> Cesium = Cs⁺
-----> Sulfur = S²⁻
2.) MgF₂
-----> Magnesium = metal and Fluorine = nonmetal
-----> Magnesium = Mg²⁺
-----> Fluorine = F⁻
3.) MgS
-----> Magnesium = metal and Sulfur = nonmetal
-----> Magnesium = Mg²⁺
-----> Sulfur = S²⁻
4.) Both cesium and strontium are metals
Answer:
0.0063mol
Explanation:
Number of moles (n) in a substance can be calculated by dividing the number of atoms (nA) of that substance by Avagadro's number i.e. 6.02 × 10^23. That is; n = nA ÷ 6.02 × 10^23
1 mol of Gold = 6.02 × 10^23 atoms
Therefore, 3.8 x 10^21 atoms of Gold will be;
3.8 x 10^21 ÷ 6.02 × 10^23
= 3.8 ÷ 6.02 × 10^ (21 - 23)
= 0.6312 × 10^-2
= 0.0063mol of Gold
Answer:
Number of moles of hydrogen are 0.022 mol.
Explanation:
Given data:
Volume of hydrogen = 546 mL
Temperature = 30°C
Pressure = 100.45 kpa
Number of moles of hydrogen = ?
Solution:
According to ideal gas equation,
PV = nRT
P = pressure
V = volume
n = number of moles
R = ideal gas constant
T = temperature
First of all we will convert the units,
Temperature = 30 + 273 = 303 K
Pressure = 100.45 /101 = 0.99 atm
Volume of hydrogen = 546 mL× 1L /1000 mL =0.546 L
Now we will put the values in formula,
PV = nRT
n = PV/RT
n = 0.99 atm × 0.546 L /0.0821 atm.L/mol.K × 303 K
n = 0.541 atm. L / 24.876 atm.L / mol
n = 0.022 mol
Answer:
The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.
Explanation:
Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.
For example CCl₄ can be shown as follows
..
.. Cl..
.. ..
..Cl..----------C----------..Cl..
..
.. Cl..
The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.
Similarly methane CH4 can also be shown.
The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.
Answer:
At the end of meiosis, there are four cells, each with 23 chromosomes, for a total of 92 chromosomes split between the four cells.
Explanation:
During meiosis, a diploid cell (46 chromosomes) replicates its DNA (making 92 chromosomes) then undergoes two cell divisions to generate four haploid cells (23 chromosomes).
These haploid cells are the gametes which, during fertilization, fuse to become a zygote with 46 chromosomes.