The atomic number of an element is the total number of which particles in the nucleus? (1 point) neutrons protons electrons protons and electrons 4. all atoms of the same element have the same (1 point) a. number of neutrons b. number of protons c. mass numbers d. mass 5. isotopes of the same element have different (1 point) a. positions on the periodic table b. chemical behavior c. atomic numbers d. mass numbers

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule

Asolution of naoh has a concentration of 25.00% by mass. what mass of naoh is present in 0.250 g of this solution? use the periodic table in the toolbar if needed. 0.0625 g what mass of naoh must be added to the solution to increase the concentration to 30.00% by mass? g