Answer:
The most important elements that we use in everyday life include carbon, hydrogen, oxygen, with smaller amounts of things like chlorine, sulfur, calcium, iron, phosphorus,nitrogen, sodium, and potassium. Apart from these, other elements include magnesium, zinc, neon, and helium are also in our daily existence.
all these element are my favourite element .......
Answer:
Explanation:
A physical change is a change in which the physical properties of matter are altered. These are properties are the forms and state.
Most physical changes are easily reversible and are pure state changes.
They do not lead to the production of new compounds.
They involve no mass change and requires little to no energy.
Examples are melting, boiling, freezing, sublimation e.t.c
Answer:
28.9%
Explanation:
Let's consider the following balanced equation.
2 FeS₂ + 11/2 O₂ ⇒ Fe₂O₃ + 4 SO₂
We can establish the following relations:
- The molar mass of Fe₂O₃ is 159.6 g/mol
- 1 mole of Fe₂O₃ is produced per 2 moles of FeS₂
- 1 mole of Fe is in 1 mole of FeS₂
- The molar mass of Fe is 55.84 g/mol
The amount of Fe in the sample that produced 0.516 g of Fe₂O₃ is:

The percent of Fe in 1.25 g of the ore is:

Answer:
Zr (Zirconium)
Explanation:
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d2