Answer:
A)Chlorine and Bromine:
They are both non metal hence they form a covalent bond due to covalent bonding.
B)Potassium and Helium:
Helium ion has a small cationic radius and distorted by the potassium ion due to polarization.
C)Sodium and Lithium:
Both are metals hence they form a metallic bond since they share electrons to the electron cloud.
Answer:
Reaction 1 is balanced but 2 is not balanced , the balance equation are :
1. 
2.
Explanation:
Balanced Equations : These are the equation which follows the law of conservation of mass .
The total number of atoms present in reactant is equal to total number of atoms present in product.
1. 
This is acid - base type reaction where
act as Acid
act as weak base
Reactant :
,
Number of atoms of :
C = 2 (
) + 1 (
)
= 2 + 1
= 3
H = 4(
) + 1 (
)
= 4 + 1
5
O = 2(
) + 3 (
)
= 5
Na = 1 (
)
= 1
Product :
,
, 
Number of atoms :
C = 1(
) + 2(
)
= 1 + 2
= 3
H = 2(
) + 3(
)
= 2 + 3
= 5
O = 1(
) + 2(
)
+2(
= 1 + 2 + 2
= 5
Na = 1(
= 1
Number of Na =1 , C = 3 , H= 5 and O =5 in both reactant and product , so it is a balanced reaction
2.
This is double displacement reaction .
Check the balancing in both reactant and products should be :
Na = 2
H = 2
Ca = 1
C = 2
O = 6
Cl = 2
4 grams of methane is <span>burned with oxygen,. Hope this helped</span>
Answer:

Explanation:
The number of valence electrons tells us the group number of the neutral atom.
The atom has 4 valence electrons.
The atom is in group 4.
Formula:

Given:
Density=3.4
Volume=500.0
Plug them into the formula:
Final answer: 1700g