A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Answer:
The true statement is:
They are formed when atoms of different elements combine.
Explanation:
Compounds are formed when atoms of different elements combine.
Atoms of different elements combine with each other to attain stable electronic configuration.
The atoms can combine with each other in two different ways:
1) By sharing the electrons
2) By exchanging electrons
When they share electrons with each other, they form a covalent bond.
When they exchange electrons, they form an ionic bond.
The atmosphere is a mixture of gasses.
Answer:
B
Explanation:
The warmer the water, the more space it takes up, and the lower its density.