Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give 
which written in simplest whole number ratios to give neutral 
Answer:
The correct answer is - sulfur.
Explanation:
In the periodic table, there are 18 groups and 7 rows or periods arranged according to their atomic number or electronic configuration. In the question, it is mentioned that the desired element atomic mass is less than the atomic mass of the selenium which is 78.96, and more than oxygen which is 15.99 with 6 electron valence and present in the third row.
As it has 6 valency of electron it must be in the 16 group of the table that comprises the 6 valency and as it is located in the 3rd row it must be sulfur that also has an atomic mass between selenium and oxygen.
The specific heat capacity the substance is calculated using the below formula
Q(heat) = Mc delta T
Q =1560 cal
m(mass) 312 g
delta T (change in temperature ) = 15 c
C= specific heat capacity=?
by making c the subject of the formula
c=Q/m delta T
= 1560 cal/ 312g x 15 c = 0.33 cal/g/c (answer B)
Answer:
1 the reproductive system. and the immune system is there to fight off any viruses or bacteria that had entered your body. If the bacteria is harmful it will be fought.
Answer:
0.808 M
Explanation:
Using Raoult's Law
where:
= vapor pressure of sea water( solution) = 23.09 mmHg
= vapor pressure of pure water (solute) = 23.76 mmHg
= mole fraction of water
∴
------ equation (1)
------ equation (2)
where; 
number of moles of sea water
number of moles of pure water
equating above equation 1 and 2; we have :
NOW, Molarity = 
As we assume that the sea water contains only NaCl, if NaCl dissociates to Na⁺ and Cl⁻; we have 
