Answer:
The answer is
<h2>4.54 g/cm³</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
mass of rock = 454 g
volume = 100 cm³
The density of the rock is
We have the final answer as
<h3>4.54 g/cm³</h3>
Hope this helps you
Answer:
C(graphite) → C(diamond), ΔH = - 0.45 kcal
CH4 + 2O2 → CO2 + 2H2O + 212,800 cal
Explanation:
C(graphite) → C(diamond), ΔH = - 0.45 kcal
CH4 + 2O2 → CO2 + 2H2O + 212,800 cal
These reactions are exothermic reaction because heat is evolved.
The energy changes occur during the bonds formation and bonds breaking.
There are two types of reaction endothermic and exothermic reaction.
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Explanation:
A column on the periodic table represents a period.
These are some of the variations observed across a period;
- Atomic radii decreases progressively from left to right due to the progressive increase in the nuclear charge without an attendant increase in the number of electronic shells.
- Ionization energy increases progressively from left to right due to decreasing atomic radii.
- Electronegativity increases from left to right.
- Electropositivity decreases across a period.
The electromagnetic is a force that combines the effects of electrical charge and magnetism. The electromagnetic force can either attract or repel the particles on which it acts.
Answer:
Chemical
Explanation:
The Chemical formula is the combination of chemical symbols and numbers that represent the elements and number of atoms within a compound.
