Answer:- The formula 
tells us that one formula unit of this compound is composed of one calcium atom, two nitrogen atoms, and six oxygen atoms.
Explanations:- Subscripts tell us about the number of atoms of the element for which they are used. For example, here the subscript of Ca is one, it means there is one calcium atom in the given one formula unit.
When we have subscripts inside and outside the parenthesis then they are multiplied and the outside subscript is considered for all the atoms present inside the parenthesis.
Here, for the given chemical formula, the subscript of N is 1 and the subscript present outside is 2. So, 1 x 2 = 2 and for oxygen, 3 x 2 = 6
So, we have one calcium atom, two nitrogen atoms and six oxygen atoms for one formula unit of given compound.
Answer:
4) 4Fe + 3O₂ → 2Fe₂O₃
Explanation:
4Fe + 3O₂ → 2Fe₂O₃
In this equation the numbers of atoms are same in both side. There are four iron and six oxygen atoms are present on left and right side of equation. That's why atoms are conserved. This equation completely followed the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Answer:
Explanation:
Force can be found by multiplying the mass and the acceleration.
The mass of the sled is 300 kilograms and the acceleration is 2 meters per second squared.
Multiply.
1 kilogram-meter per second squared is equal to 1 Newton. Therefore, 600 kilograms-meter per second squared is equal to 600 Newtons.
The force used on the sled is 600 Newtons.
Hey There!
Molar mass KBrO2 = 151.0011 g/mol
1 mole KBr --------- 151.0011 g
So in 0.168 moles :
mass = number of moles * molar mass
mass = 0.168 * 151.0011
mass = 25.36 g of KBrO2
When a half-life passes, only half of the mass of the sample stays. So to get to 25 g from 200, let's see how much half-lives will pass.
200÷2=100
100÷2=50
50÷2=25
The answer to that is 3 half-lives, or
3 × 5730 = 17190 years
