Answer:
A sample of water boils and releases gas.
Explanation:
Physical change is a change where no any chemical reaction takes place only the chemical composition of matter changes. It is a reversible process .
Burning of newspaper, rusting of iron, plant changes carbon dioxide and water into sugar (photosynthesis) are chemical reaction and irreversible process.
Answer: A. O2
Explanation:
If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), subsequent analysis will show that 18O first appears then 3-phosphoglycerate molecule produced by the algae.
A. Sodium is correct.
Sodium is an alkali metal.
Aluminum is a post-transitional metal- still a metal but it’s character is not as metallic as sodium.
Silicon is a metalloid- it has characteristics from both the metals and the non-metals.
Phosphorous is a non-metal.
It will be:
b. Alkyne* series
* You have done a spelling mistake here. It will be "Alkene" not "Alkyne".
The answer is A. Water
Bronsted-Lowry base compounds are those that can accept protons
Bronsted-Lowry Acid Compounds are those that can recieve one
Water / H2O is an Amphoteric compund which mean that its molecul can act as a Base and Acid compound, so the answer is A.