An index fossil is a fossil that is useful for dating and correlating the strata in which it is found.
Or it is a fossil that helps you find the date where it has been found. I rephrased that.
- The difference between single displacement reaction and double displacement reaction are:
Explanation:
in the chemical reaction an atom in a molecule is replaced by another atom forming the end product .this type of chemical reaction involved only two reactants for example zinc + copper sulphate give us copper sulphate + copper.double displacement reaction is the reaction in which two compounds react together to form two other compounds by mutual exchange of other ions is called double displacement reaction.this type of reaction is involved two or more than two reactants.for example AG and O3 + NaCl give us agcl + nano3
Answer:
Crystalization is solidfying of atoms or molecules or things,,it can be speeded up depends on nature of something in terms of it's molecular force of attraction eg sand and loam soil also temperature and pressure above the sure to be crystalized
An igneus rock is formed where magma(molten rock) cool and solify(crystalized especially in volcanoes areas
Answer:

Explanation:
The expression for the work done is:

Where,
W is the amount of work done by the gas
R is Gas constant having value = 8.314 J / K mol
T is the temperature
P₁ is the initial pressure
P₂ is the final pressure
Given that:
T = 300 K
P₁ = 10 bar
P₂ = 1 bar
Applying in the equation as:




The reaction will produce 12.1 g Ag₂S.
<em>Balanced equation</em> = 2Ag + S ⟶ Ag₂S
<em>Mass of Ag₂S</em> = 10.5 g Ag × (1 mol Ag/107.87 g Ag) × (1 mol Ag₂S/2 mol Ag)
× (247.80 g Ag₂S/1 mol Ag₂S) = 12.1 g Ag₂S