Answer:
<em>The correct option is A) The atom has changed over the years.</em>
Explanation:
Option A is not correct because an atom does not change. It remains the same always. The structure of an atom will always contain neutrons, protons and electrons.
Scientific theories tend to change over time as new information is brought up. Novel techniques lead to more advanced experiments and results. As a result, a scientific theory is subjected to change whenever evidence is found for a new theory which challenges the older one.
The atomic theory has changed many times due to novel scientific techniques and experiments.
Elements are ordered from left to right, increasing atomic number as they go. The periodic table allows us to find out and predict things about elements that haven’t been discovered yet!
Explanation:
The answer to questions are
A) 4
B) 3
C) 5
D) 3
E) 3
Answer:
The chemist needs to react 40 g of sulfur with 60 g of oxygen to make 100 g of sulfur trioxide.
Explanation:
2S (s) + 3O₂ (g) → 2SO₃ (g)
64g + 96g → 160 g
32g + 48g → 80 g
x + y → 100 g
1 mol SO₃ ___ 80g
n _______ 100g
n = 1.25 mol SO₃
1 mol S ___ 32 g
1,25 mol S __ 40 g
1 mol O₂ ___ 32 g
1,875 mol O₂ ___ 60 g
Explanation:
Since mole ratio of O2 : NH3 = 7 : 4,
Volume of NH3 = 50dm³ * 4/7 = 28.57dm³.
