4li + o2 ----> 2li2o
8 x
cross multiply 8x2 ÷ 4x
x=4
the answer is 4
Is not a single replacement
<h3>Further explanation</h3>
A single replacement reaction is a chemical reaction in which one element replaces the other elements of a compound to produce new elements and compounds
Reactions
A+BC--> AC+B
Metal halogens can force metal halide ions in the order F> Cl> Br> I
Oxidation : F₂> Cl₂> Br₂> I₂
Reaction
NaBr+I₂ -> NaI+Br₂
Then the reaction will not occur because I₂ cannot oxidize Br, or the reaction is said to be non-spontaneous
Answer:
Q1: Bubbles (gas formation)
Dissolving ( if solute is an ionic compound)
Color change
Q2: Fire burning
Salt dissolving
Q3: Bubbles (gas formation)
Color change
Dissolving ( if solute is an ionic compound)
Explanation:
Bubbles (gas formation)
Gas formation is mostly taken as an indicator for a chemical reaction, mostly in acid base reactions. Because when acid and base reacts water and carbon dioxide produces.
Dissolving of salt
Dissolving of salt in water is an example of a chemical change. Because when we put salt (NaCl) in water it changes into its ions (Na⁺ Cl⁻) by losing or gaining electrons. These Ions have totally different properties from the parent salt. So it is a chemical change.
Color change
Mostly we take color change as an indicator of a chemical change but it is not necessary. For example when we add two colors in a beaker its changes into a 3rd color without any chemical reaction.
Fire burning
Fire burning is an example of a chemical change. For example during wood burning, a chemical reaction takes place which changes the into ash and CO₂. the reactants and products have totally different properties.
CO2 has a linear geometric shape due to the two sigma bonds between the carbon and oxygen valence electrons. Both oxygen molecules are sp2 hybridized meaning they both have one sigma bond and two pairs of un bonded electrons.
I think the answer is a). While though peptides and proteins are formed by amino acids. But the proteins have more complex structure than peptided and this leads to the higher function of proteins over peptides.
