Answer:
a)Atomic number
Explanation:
Element symbol signifies the element. For eg, Na is sodium. Mass number is the sum of protons and neutrons of an atom of an element. Atomic mass is the molar mass of the given element. Finally, atomic number is unique to each element because it signifies the number of protons of that element. EACH ELEMENT has their UNIQUE number of protons. For eg, atomic number of hydrogen is 1 because it has 1 proton, NO OTHER ELEMENT HAS ATOMIC NUMBER 1 because NO OTHER ELEMENT HAS 1 proton.
E=MC(delta)T
=20.0g x 9.00J/g x (94.4-22.8) C
= 12,924.0 J
Moles of PF₃ : 4
<h3>Further explanation</h3>
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction

1.25 moles of P₄(s) is reacted with 6 moles of F₂(g)
Limiting reactant : the smallest ratio (mol divide by coefficient)
P₄ : F₂ =

mol PF₃ based on mol of limiting reactant(F₂), so mol PF₃ :

Answer:
curium
−
243
,
252
/
99
Es,
251
/
98
Cf,
214
/
82
Pb
Explanation: Im not very good with this but here ya go!
Answer:
Via covalent bonds
Explanation:
Atoms in molecules are bonded together via covalent bonds. Covalent bonds are bonds that are formed by sharing of the valence electrons between two atoms.
The atoms can be of the same kind or of different kinds.
- In most molecules, the two atoms are connected by sharing of their valence electrons.
- This way, each atom can attain stability by becoming isoelectric with the nearest noble gas.
- Some molecules are monoatomic, some are polyatomic.