no sefdrcdftrgfkjj jhhhgfd
<span>In crystallography, the terms crystal system, crystal family, and lattice system each refer to one ... In total there are seven crystal systems: triclinic, monoclinic, orthorhombic, ..... A polar crystal possess a "unique" axis (found in no other directions) such ... lattices in three dimensions; each can apply in one lattice system only.</span><span>
</span>
Answer: B) 2 (as indicated by electron distribution shown), but taking into account the real properties of this element, 4,7,8 also occur (see below).
Explanation:
This is the electron complement/atomic number of ruthenium, which actually has the structure [Kr] 5s1 4d7
Nevertheless, Ru does not form Ru(I) compounds and few Ru(II) compounds (RuCl2, RuBr2, RuI2). It also forms Ru(III)Cl3 and a larger number of Ru(IV) compounds, e.g. RuO2, RuS2. It also forms RuO4
Answer:
4 moles of neon
Explanation:
Given data:
Number of moles of neon = ?
Number of atoms of neon = 2.4×10²⁴ atoms
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For given neon atoms:
1 mol = 6.022 × 10²³ atoms
2.4×10²⁴ atoms × 1 mol / 6.022 × 10²³ atoms
0.4×10¹ mol = 4 mol
Answer:
a) 
b) 
c) 
d) 
Explanation:
For neutral atoms:
Atomic Number (Z)= number of protons = number of electrons
Mass number (A) = number of protons + number of neutrons
For ions with positive net charge:
Number of protons = Z + net charge
For ions with negative net charge:
Number of protons= Z - net charge
a) A = 71, Charge = +3
Number of electrons = 28
Number of protons = 28 +3 =31
b) A = 35, Z = 45+35=80, Charge = -1
Number of protons =35
Number of neutrons = 45
Number of electrons = 36
Charge = Number of protons- Number of electrons =35-36 = -1
c) Charge = +4
Number of electrons = 86
Number of protons = Z = 86+4 = 90
mass number = A = 90+142 = 232
d) Charge = +2
Atomic number = Number of protons = Z = 38
mass number = A = 87
