Answer: 2s and 2p
Explanation: Carbon is an element with atomic number of 6 and thus contains 6 electrons. The electrons are filled in order of increasing energies and follows Afbau's rule.The electrons are singly filled first in each orbital having same spin, then only pairing occurs. This rule was known as Hund's Rule.
The valence electrons are the electrons which are present in last shell. Thus valence electrons are 4, two in s and 2 in p orbitals.
1) Chemical equation
Cu + 2AgNO3 ---> Cu (NO3)2 + 2Ag
2) molar ratios
1 mol Cu: 2 moles AgNO3 : 1 mol Cu (NO3)2 : 2 mol Ag
3) Convert 12. 83 * 10^23 atoms of Cu in moles
12.83 * 10 ^ 23 atoms / (6.02 * 10^23 atoms / mol) = 2.131 mol Cu
4) Use the proportions
2.131 mol Cu * 2 mol Ag / 1 mol Cu = 4.262 mol Ag
5) Use the atomic mass of silver to convert 4.262 mol in grams
mass = number of moles * atomic mass = 4.262 mol * 107.9 g / mol = 459.9 grams
Answer: 459.9 g
Hydrogen bonds are not like covalent bonds. They are nowhere near as strong and you can't think of them in terms of a definite number like a valence. Polar molecules interact with each other and hydrogen bonds are an example of this where the interaction is especially strong. In your example you could represent it like this:
<span>H2C=O---------H-OH </span>
<span>But you should remember that the H2O molecule will be exchanging constantly with others in the solvation shell of the formaldehyde molecule and these in turn will be exchanging with other H2O molecules in the bulk solution. </span>
<span>Formaldehyde in aqueous solution is in equilibrium with its hydrate. </span>
<span>H2C=O + H2O <-----------------> H2C(OH)2</span>
What is the difference between calories and kilocalories? The "calorie" we refer to in food is actually kilocalorie. One (1) kilocalorie is the same as one (1) Calorie (upper case C). A kilocalorie is the amount of heat required to raise the temperature of 1 kilogram of water one degree Celsius.
Answer:- 64015 J
Solution: There is 4250 mL of water in the calorimeter at 22.55 degree C.
density of water is 1 g per mL.
So, the mass of water = 
= 4250 g
Final temperature of water after adding the hot copper bar to it is 26.15 degree C.
So, 
for water = 26.15 - 22.55 = 3.60 degree C
Specific heat for water is 4.184 
The heat gained by water is calculated by using the formula:
where, q is the heat energy, m is mass and c is specific heat.
Let's plug in the values in the formula and do the calculations:
q = 64015 J
So, 64015 J of heat is gained by the water.
