Answer:
Because X-rays have wavelengths similar to the size of atoms
Answer:
It is composed of protons, which have a positive charge, and neutrons, which have no charge. Protons, neutrons, and the electrons surrounding them are long-lived particles present in all ordinary, naturally occurring atoms. Other subatomic particles may be found in association with these three types of particles.
Explanation:
Atoms consist of three basic particles: protons, electrons, and neutrons. The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge). The outermost regions of the atom are called electron shells and contain the electrons (negatively charged).
Pb(NO₃)₂ ⇒limiting reactant
moles PbI₂ = 1.36 x 10⁻³
% yield = 87.72%
<h3>Further explanation</h3>
Given
Reaction(unbalanced)
Pb(NO₃)₂(s) + NaI(aq) → PbI₂(s) + NaNO₃(aq)
Required
- moles of PbI₂
- Limiting reactant
- % yield
Solution
Balanced equation :
Pb(NO₃)₂(s) + 2NaI(aq) → PbI₂(s) + 2NaNO₃(aq)
mol Pb(NO₃)₂ :
= 0.45 : 331 g/mol
= 1.36 x 10⁻³
mol NaI :
= 250 ml x 0.25 M
= 0.0625
Limiting reactant (mol : coefficient)
Pb(NO₃)₂ : 1.36 x 10⁻³ : 1 = 1.36 x 10⁻³
NaI : 0.0625 : 2 = 0.03125
Pb(NO₃)₂ ⇒limiting reactant(smaller ratio)
moles PbI₂ = moles Pb(NO₃)₂ = 1.36 x 10⁻³(mol ratio 1 : 1)
Mass of PbI₂ :
= mol x MW
= 1.36 x 10⁻³ x 461,01 g/mol
= 0.627 g
% yield = 0.55/0.627 x 100% = 87.72%
Answer:
Explanation:
1...............
CoCl₂ is an ionic compound
CF₄ is molecular
BaSO₄ is an ionic compound
NO is molecular
An ionic compound is a compound which forms between a metal and non-metal. It involves the formation of a bond between two ions of significant electronegative difference. It results from the electrostatic force of attraction between two atoms in which one has lost an electron(metal) and the other that has gained an electron(non-metal).
CoCl₂ is an ionic compound
BaSO₄ is also ionic
A molecular compound is formed as a result of covalent bonds between atoms. This is due to the fact that the two atoms have similar electronegativities and would both pull the shared electrons closely. Most molecules are usually formed this way.
CF₄ and NO are both molecular compounds
2...... The ionic compounds are the ones containing metals:
In CoCl₂ the metal is Co, cobalt
BaSO₄ has Ba
Co is a transition metal. Transition elements are known to have various oxidation states. This implies that they can form more than one type of ion. The oxidation number of Co are -1, 0, +1, +2, +3 and +4
Ba will only form one type of ion as an alkaline earth metal. It has an oxidation state of +2 only. It will only form one type of ion.