Ionic: transfer of electrons
Covalent: sharing of electrons
Metallic: sharing of free electrons in a structure of cations
Answer:-
Alpha decay
Explanation:-
Uranium 238 has atomic number 92 and mass number 238.
Thorium 234 has atomic number 90 and mass number 234.
So, the change in atomic number as uranium 238 disintegrates into thorium234 = 92 – 90 = 2
So, the change in mass number as uranium 238 disintegrates into thorium234= 238 – 234 = 4
We know that when an alpha particle is emitted, the mass number decreases by 4 and the atomic number decreases by 2.
So when an atom of uranium 238 undergoes radioactive decay to form an atom of thorium-234, alpha decay has occurred.
4,410 kJ
Explanation:
Gravitational Potential Enegry (GPE) is calculated as;
GPE = <em>m*g*h</em> where;
m = mass (kg)
g = gravity (m/s²)
h = height (meters)
= 90 * 9.8 * 5000
= 4,410,000 joules
= 4,410 kJ
The gallionella bacteria reaction
that is Fe2+ → Fe3+ is example of oxidation reaction (answer A)
Explanation
oxidation reaction reaction occurs when electrons are lost during reaction by a molecule or ion or atom. when oxidation occurs the oxidation state of the molecule or ion or atom increases. For this reason Fe2+ → Fe3+ is a oxidation reaction since the oxidation state move from oxidation state 2 to 3
