The table below gives some characteristics of element y. characteristics of element y values mass number 11 number of neutrons in a single atom 6 average atomic mass (grams/mole) 10.81 what is the identity of element y? c b na s

Answer is: the identity of element Y is B (boron).

A(Y) = 11; mass number.

A = p⁺ + n°; mass number is the total number of protons and neutrons in a nucleus.

n°(Y) = 6; number of neutrons in atom Y.

p⁺(Y) = A(Y) - n°(Y).

p⁺(Y) = 11 - 6.

p⁺(Y) = 5; number of protons in atom Y.

Z = p⁺; atomic number.

Atomic number is the number of protons, which is characteristic of a chemical element, boron is an element with atomic number 5.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >