The answer is letter C.
Because we classify something as a star when it is: a large ball of gas that undergoes nuclear fusion. Given this definition, a comet is not a star. A comet is a ball of ice and dirt hurtling through space, it shines only because it reflects ligh
Answer:
A. Metallic bond
Explanation:
Think about it: copper and tin are both common metals. That's how we know it's a metallic bond!
Why not B: Covalent bonds are between two nonmetals.
Why not C: Ionic bonds are between a nonmetal and a metal.
Why not D: Paired bond isn't a common phrase in chemistry.
Answer: a) 
b) 
c) 
d) 
Explanation:
General representation of an element is given as:_Z^A\textrm{X}
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
It is characteristic of a particular element.
Atomic number = Number of electrons = Number of proton
a) Z 74, A 186:
b) Z 80, A 201:
c) Z 34, A 76:
d) Z 94, A 239.:
Answer:
Atoms must have similar electronegativities in order to share electrons in a covalent bond.
Explanation:
Covalent bonding is one of the bondings that occurs between the atoms of elements. It is the bonding in which atoms share their valence electrons with one another. However, the ELECTRONEGATIVITY, which is the ability of an atom to be attracted to electrons play a major role in the formation of covalent bonds.
When atoms of different electronegativities combine, the more electronegative atom pulls more electrons towards itself, hence, an IONIC bond is formed. However, when the electronegativities of the atoms are similar, the sharing of their electrons becomes stronger. Hence, ATOMS MUST HAVE SIMILAR ELECTRONEGATIVITIES in order to share electrons in a covalent bond.
Answer:
Na(s) + C(s, graphite) + 1/2 H₂(g) + 3/2 O₂(g) → NaHCO₃(s)
Explanation:
The standard formation reaction is the synthesis of 1 mole of a substance from its elements in their most stables forms under standard conditions. The balanced chemical equation is:
Na(s) + C(s, graphite) + 1/2 H₂(g) + 3/2 O₂(g) → NaHCO₃(s)
