The group VIA elements are called chalcogens because most ores of copper (Greek chalkos) are oxides or sulfides, and such ores contain traces of selenium and tellurium.
Answer:
Here's what I get.
Explanation:
Your unbalanced nuclear equation is:

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
95 = x + 2, so x = 95 - 2 = 93
243 = y + 4, so y = 243 - 4 = 239
Element 93 is neptunium, so the nuclear equation becomes
Answer:
Bonds basically differs with each other due to sharing of electrons .
Explanation:
There are majorly three kinds of bonds
1. Ionic bonds which forms due to an element donate an electron to another element completely .
2. covalent bonds which forms with the mutual sharing of electrons b/w two atoms .
3. metallic bonds which forms b/w metals & they share electrons due to electron negativity difference b/w two atoms or elements