Answer:
Measuring its density and comparing your result to a list of known densities, or other properties that give you useful info
Explanation:
You can use observations about substances to form a hypothesis about the substance by comparing it to others. Ex: if something is magnetic it must be made of one or more of the elements iron, cobalt, or nickel.
A.
Explanation:
Pioneer plants are to plants species that appear first in virgin land – such an after a volcanic eruption. They are mainly lower plants such as lichen, fungi, and noses. These species can grow on rocks and break them down over time to form soil. This is due to the fact that the plants have very shallow roots that can even grow in the small crevices of rocks and can draw water from the atmosphere – moisture. This releases the nutrients in the rocks and makes them available to higher plants that have deeper roots. The ecology of the region will ultimately be succeeded by a climax community over time, mainly dominated by tree species.
OH- is common to bases.
Explanation:
The base is a is an ionic compounds which when placed in aqueous solution dissociates in to a cation and an anion OH-.
The presence of OH- in the solution shows that the solution is basic or alkaline.
From Bronsted and Lowry concept base is a molecule that accepts a proton for example in NaOH, Na is a proton donor and OH is the proton acceptor.
A base accepts hydrogen ion and the concentration of OH is always higher in base.
There is a presence of conjugate acid and conjugate base in the Bronsted and Lowry acid and base.
Conjugate acid is one which is formed when a base gained a proton.
Conjugate base is one which is formed when an acid looses a proton.
And from the Arrhenius base Theory, the base is one that dissociates in to water as OH-.
Among BF₃, NF₃, OH⁻ and ALCl₃ both NF₃ and OH⁻ acts as a lewis base.
Explaination:
According to lewis theory of acid and base, base is a specie which has either lone pair of electrons or is negatively charged. So, in the given compounds Nitrogen trifluoride contain lone pair of electron on nitrogen and Hydroxide contains a negative charge on oxygen. And botha are capable to donate these electrons to a lewis acid (electrophiles).
thx but it's actually 143
