Answer:
a.) It is a chemical reaction because a new substance was formed and a colour change occurred in the reaction.
b.) Iron- Metallic element
sulpher- Non-Metalic element
Iron Sulphide- Compound
HOPE IT HELPS....
The density of water is 1.0 grams per milliliter then it will be sink in water
Density is a word we use to describe how much space an object or substance takes up in the volume and in relation to the amount of matter in that object or substance its mass) and another way to put it is that density is the amount of mass per unit of volume
Here given density is 1.0 grams per milliliter and it will be sink in water because the density of water in 1.0 g/ml and this object is more dense than water and the density of an object determines whether it will float or sink in another substance and an object will float if it is less dense than the liquid it is placed in and an object will sink if it is more dense than the liquid it is placed
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Answer:
In a chemical equilibrium, the forward and reverse reactions occur at equal rates, and the concentrations of products and reactants remain constant. A catalyst speeds up the rate of a chemical reaction, but has no effect upon the equilibrium position for that reaction.
Explanation:
Answer: 193 mg of theobromine are present in the sample.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.
To calculate the moles, we use the equation:
1 mole of theobromine 
weigh = 180 g
of theobromine weigh = 
(1g=1000mg)
193 mg of theobromine are present in the sample.
