Answer:
oxygen is a present in our atmosphere and mixed with other gases on the surrounding screen plants are also measure source of getting oxygen they take carbon dioxide from making their food by for the cities and give away oxygen in return
Explanation:
most of the earth oxygen comes from tiny Ocean plants are called phytoplaston
Answer:
0.49 mol
Explanation:
Step 1: Write the balanced equation
Mg + 2 HCI ⇒ MgCl₂ + H₂
Step 2: Calculate the moles corresponding to 12 g of Mg
The molar mass of Mg is 24.31 g/mol.

Step 3: Calculate the moles of H₂ produced by 0.49 moles of Mg
The molar ratio of Mg to H₂ is 1:1. The moles of H₂ produced are 1/1 × 0.49 mol = 0.49 mol.
4 sig fig in that expression
I'm not to sure but try soy