In the case of the liquid meniscus, a concave meniscus that is what one usually observes takes place when the molecules of the liquid are fascinated towards the container. This takes place with water and a glass tube. A convex meniscus takes place when the molecules exhibit a stronger attraction with each other in comparison to the container, as in the case of glass and mercury.
The shape of the liquid meniscus is determined by the relative magnitudes of the cohesive forces in the liquid and adhesive forces between the liquid and its container.
This is an acid-base reaction where HF is the acid and H2O is the base (it's amphoteric and can be an acid or a base). The products would then H3O+ (the conjugate acid) and F- (the conjugate base). Now, we can simply construct a reaction using the found products and reactants. This acid-base reaction would be HF + H2O <--> H3O+ + F-.
Hope this helps!
Answer:
3,4
Explanation:
Hydrogen has no other electron hence there is no screening of the valence electron by inner electrons. It is the lightest known element with a relative molecular mass of 2. Screening effect refers to the fact that inner or core electrons prevent the outermost electron from feeling the attractive force of the nucleus.
Answer:
Isotopes are basically atoms of an element that have an unequal number of neutrons and protons. Of course the proton number remains the same, but the neutron number either decreases or increases, which leads to an overall change in mass. However, no chemical properties of the atom/element are changed as the electrons are the same number and do not react. In regards to Helium 4, the original number of neutrons in Helium is 2, and protons 2 as well. We see an equal number of neutrons and protons, hence an unchanged mass, and the element is <em>not</em> an isotope.
Answer:
(A) N4H6 (B) H2O (C) LiH (D) C12H26
Explanation:
The given compounds have been arranged from left to right in order of increasing percentage by mass of hydrogen.
The percent by mass of hydrogen can be calculated by mass of hydrogen in that compound divided by total mass of that compound and finally multiplying the result with 100 to obtain the required percentage.
