Answer: The correct option is 3.
Explanation: We are given a compound which is made up of iron and oxygen only. The ratio of the two are given as:
This means that, number of iron ions are 2
Number of oxide ions are 3
From the above information, the formula becomes : 
The valency of iron = 3
Valency of oxide = 2
This compound is named as iron (III) oxide.
Hence, the correct option is 3
Gas is not a liquid, hope this helps, o and next time you might wanna put the answer choices thanks
Answer is: d). 1-propanol. Because between two molecules of 1-propanol can for form hydrogen bond, between hydrogen and oxygen in hydroxy group.
1) Chemical formula for propanal is CH₃-CH₂-CH=O. Propanal is a saturated three carbon aldehyde (have a carbonyl center).
2) Chemical formula for propane is CH₃-CH₂-CH₃. Propane is a three carbon alkane (acyclic saturated hydrocarbon).
3) Chemical formula for propanone is (CH₃)₂-C=O. Propanone or acetone is he simplest and smallest ketone.
4) Chemical formula for propanol is CH₃-CH₂-CH₂-OH. 1-propanol is a primary alcohol.
Hydrogen bond is
an electrostatic attraction between two polar groups that occurs when
a hydrogen atom (H), covalently bound to a
highly electronegative atom such as flourine (F), oxygen (O) and
nitrogen (N) atoms.
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.
Answer:
Cell membranes (plasma membranes) help organisms maintain homeostasis by controlling what substances may enter or leave cells.
