Answer:
D. 1
Explanation:
Hydrogen is the chemical element with the symbol H and atomic number 1. With a standard atomic weight of 1.008, hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.
Answer:
C. They don't react with other elements to form compounds
Explanation:
The elements in Group 18 of the periodic table are called "inert", or noble gases.
These elements have their valence shell (the outermost shell of the atom) full of electrons, so they do not gain/give off electrons, and therefore, they do not react with other elements, so they do not form compounds.
In fact, normally the elements try to gain/give off electrons in order to fullfill their outermost shell (the valence shell). For instance, an atom that has 1 electron only in its valence shell, try to "give away" this electron in order to have its outermost shell completed. On the other hand, an atom which has 7 electrons in its valence shell tries to "gain" one electron in order to fullfill the valence shell.
Noble gases, instead, have already 8 electrons in their valence shell, so their valence shell is already completed, therefore they do not react with other elements, and therefore they are called "inert".
The answer would be C!!!!!!!!!!!!!!!!!!
Answer:
Option 4
Explanation:
Hydrochloric acid is a strong one, that gives protons to medium. It can be dissociated as this:
HCl → H⁺ + Cl⁻
M means Molarity. It is a sort of concentration that indicates the moles of solute in 1L of solution.
M = moles / volume (L)
We can also say M = mmoles / mL of solution
M . mL = mmoles
0.453 M . 62.85mL = 28.5 mmoles
If we divide by 1000 → 28.5 mmol . 1 mol / 1000 mmol = 0.0285
Answer:
Magnifying glass or a special device that resembles a handheld microscope, used to observe ink placement of printers
Explanation:
