Answer:
D. Atoms are like solid balls
Explanation:
John Dalton proposed that all matter is composed of very small things which he called atoms. This was not a completely new concept as the ancient Greeks (notably Democritus) had proposed that all matter is composed of small, indivisible (cannot be divided) objects. When Dalton proposed his model electrons and the nucleus were unknown.
The correct one is Respiratory Distress !!
As rest are not concerned with air pollution !!
Answer:
I'm pretty sure the answer is C.
A. phase changing. Physical change is any change in matter that involves the substance going from one physical state to another, and phase change is most commonly used to describe transitions between solid, liquid and gaseous states of matter.
Answer:
Option 6 ) Neutralization
Explanation:
For this case, the missing coefficient would be a "6" before the H₂O, within final products (right side of the equiation), hence, the final reaction should be:
2H₃PO₄ + 3Ba(OH)₂ ------> Ba₃(PO₄)₂ + 6H₂O
You should have in mind that the amount of atoms at each side of the chemical equation should be the same, so as to comply with the principle of mass conservation. If you add "6" on the left side of the H₂O, the equation will be balanced (for each side, lef and right, you will have: 12H, 2P, 14O and 3Ba)
Lastly, this is a chemical neutralization reaction, where an acid (H₃PO₄) is reacting with a base (Ba(OH)₂) in order to finally obtain a neutral salt (Ba₃(PO₄)₂) and water (H₂O)
