Answer:
Check explanation.
Explanation:
Electron affinity simply means the ability of an atom to gain an electron. Electron affinity can also be defined as the change in energy of a neutral atom in the gaseous phase when an electron is added to the atom to form a negative ion.
Electron affinity characteristics trends is that it increases upward for the groups and from left to right across periods of a periodic chart.
Both Bromine and Iodine are both found in group 7/17 , that is the Halogens on the periodic chart. Group seven element has 7 valence electrons(that is, it remains 1 electron for them to reach their octet). Hence, when an electron is added to these Halogens, energy will be released.
WHAT CAUSES THE DIFFERENCES in ELECTRON AFFINITY for bromine and IODINE are;
(1). Atomic size: iodine atom is larger than a bromine atom. Therefore, outermost electrons of Iodine are located further away from the nucleus.
(2). The shielding effect: Iodine has an extra full shell of core electrons between the nucleus and the outermost shell and these extra core electrons will shield the outermost electrons from the nucleus.
So, less energy will be released when one mole of electrons is added to one mole of Iodine atoms as compare with Bromine atoms
Molar mass of lead is 207.2 grams/mole (according to the periodic table)
Molar mass of Sulfate
Sulfur + 4 Oxygen
Molar mass of Sulfur + molar mass of 4 oxygen = 96 grams/mole for sulfate
207.2 + 96.6 = 303.8 grams/mole for Lead(II) Sulfate (I might be .5 grams of, down or up)
Answer:
E = 1.8 x 10⁵ J/mol
Explanation:
We are being asked the enery per mol for an emission line corresponding to 649 nm.
The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,
E = hν
We also know that the frequency is given by
ν = c/λ
where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by
E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m
E = 3.1 x 10 ⁻¹⁹ J/ photon
(Note the wavelength has to be in nanometers (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.
E = 3.1 x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol
E = 1.8 x 10⁵ J/mol
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