The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
Thus, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Nitrogen could form 3 covalent bonds if each of its unpaired electrons participates in one bond.
Nitrogen atom forms 3 bonds based on octet rule, because it has 5 valence electrons. That means it needs 3 bonds or three more electrons.
<h3>Further Explanation;</h3><h3>Chemical bond </h3>
- A bond is a type of force that is formed between atoms of different through the sharing or transfer of electrons.
<h3>Octet rule</h3>
- According to the octet rule for an atom to be stable it must have maximum number of electrons in its outermost energy level. Therefore an atom with four electrons requires four more electrons to attain stability.
<h3>Types of chemical bonds.</h3><h3>Covalent bond </h3>
- This is a type of bond that is formed between non-metal atoms. It is formed as a result of sharing electrons between non-metal atoms involved.
- When atoms involved contribute equal number of electrons to the bond formation, the type of bond is known as covalent bond
- A covalent bond may be a dative covalent bond, when the shared electrons come from one atom.
<h3>Ionic bond </h3>
- This is a type of bond that occurs between metal ions and non-metal ions. Ionic bond occurs as a result of transfer of electrons from one metal atom to another non-metal atom.
- After the transfer of electrons, metal atom loses electron to form a cation while the non-metal atom gains electrons to form an anion.
<h3>
Other types of chemical bonds include;</h3>
- Hydrogen bonds
- Metallic bonds
- Dipole-dipole interactions, etc.
Keywords: Chemical bond, covalent bond, atom
<h3>Learn more about:</h3>
Level: High school
Subject: Chemistry
Topic: structure and bonding
Sub-topic: Covalent bond
Answer: The reaction is exothermic. The value of q is -542 kJ.
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.
Thus
evolves heat , it is exothermic in nature. The value of q is -542kJ.
Energy would be the correct answer
Most Favored Nation status is an economic position in which a country enjoys the best trade terms given by its trading partner. That means it receives the lowest tariffs, the fewest trade barriers, and the highest import quotas (or none at all).
I got this from google, hope it helps! :)