A covalent or molecular bond is the sharing of electrons between atoms. You can tell how many covalent bonds an atom can make by the number of electrons it has available to share along with using the octet rule which helps determine the number electrons that atoms can have in their outer most orbital, the maximum of eight, hence octet rule, from 1, 2, 3, or up to a maximum of r covalent bonds.
Al(s) + 2AgNO3(aq) = Al(NO3)3(aq) + 3 Ag (s)
is a single replacement reaction
A single replacement reaction is a type of chemical reaction were element react with a compound and the element take place of another element in that compound. In the reaction above Aluminium (Al) take the place of silver (Ag) from it compound.that is AgNO3. single replacement reaction is possible because aluminium is in high in reactivity series as compared to silver.
43.56 grams of are produced if 16g of CH4 reacts with 64g of O2.
Explanation:
Balance equation for the reaction:
CH4 + 2O2⇒ CO2 +2H2O
Data given : mass of CH4 =16 grams atomic mass = 16.04 grams/mole
mass of water 36 gram atomic mass = 18 grams/moles
mass of CO2=? atomic mass = 44.01 grams/mole
number of moles = 
equation 1
number of moles in CH4
n = 
= 0.99 moles
Since combustion is done in presence of oxygen hence it is an excess reagent and methane is limiting reagent so production of CO2 depends on it.
From the equation
1 mole of CH4 gave 1 mole of CO2
O.99 moles of CH4 will give x moles of CO2
= 
x = 0.99 moles of carbon dioxide
grams of CO2 = number of moles x atomic mass
= 0.99 x 44.01
= 43.56 grams of CO2 is produced.
The nucleus (plural, nuclei) houses the cell's genetic material, or DNA, and is also the site of synthesis for ribosomes, the cellular machines that assemble proteins. Inside the nucleus, chromatin (DNA wrapped around proteins, described further below) is stored in a gel-like substance called nucleoplasm.
