"Physical changes occur when objects or substances undergo a change that does notchange their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances."
Answer:
an acid is a substance which produces hydrogen ions as the only as the only positive ion when dissolved in water.
Answer:
Sunlight
Explanation:
Photosynthesis is the process where by plants manufacture their own food through conversion of carbon(iv)oxide and water in presence to sunlight to produce glucose and oxygen as by product.
The reaction is photo-catalyzed and would only take place in the presence of sunlight.
6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂
Answer: -
1 mol
Explanation: -
Number of moles of Sulphur S = 7
Number of moles of O2 = 9
The balanced chemical equation for the reaction is
2S (s)+3 O2 (g)→2SO3(g)
From the above reaction we can see that
3 mol of O2 react with 2 mol of S
9 mol of O2 will react with

= 6 mol of S
Unreacted S = 7 - = 1 mol.
If a reaction vessel initially contains 7 mol S and 9 mol O2
1 mole of s will be in the reaction vessel once the reactants have reacted as much as possible
FeNi or NiFe is an acronym used to refer a family of iron alloys.
<h3>What is alloy?</h3>
An alloy is a mixture of chemical elements that contains at least one is a metal.
<h3>Alloy of iron</h3>
The alloy of iron-nickel can be abbreviated as FeNi, which implies iron-nickel.
where;
- Fe stands for iron
- Ni stands for Nickel
Thus, FeNi or NiFe is an acronym used to refer a family of iron alloys.
Learn more about iron alloys here: brainly.com/question/24842164