Question

element # protons # neutrons # electrons mass number type your answer... type your answer... type your answer... 9 19 n type your answer... 8 type your answer... type your answer... type your answer... 8 type your answer... 14 helium 2 he 4.0026 boron 5 b 10.811 carbon 6 c 12.011 nitrogen 7 n 14.007 oxygen 8 o 15.999 fluorine 9 f 18.998 neon 10 ne 20.180 aluminum 13 al 26.982 silicon 14 si 28.086 phosphorus 15 p 30.974 sulfur 16 s 32.065 chlorine 17 cl 35.453 argon 18 ar 39.948

Explanation:

Step1: Identify element with 9 electrons

In a neutral atom, number of protons = number of electrons. From the periodic - table, the element with 9 electrons (and 9 protons) is fluorine (F).

Step2: Calculate neutrons for F

Mass number = number of protons+number of neutrons. For F with mass number 19 and 9 protons, number of neutrons = 19 - 9=10.

Step3: For nitrogen (N)

From the periodic - table, nitrogen has 7 protons. In a neutral atom, number of electrons = number of protons, so number of electrons for N is 7. Mass number = number of protons + number of neutrons. Given 7 protons and 8 neutrons, mass number = 7 + 8 = 15.

Step4: Identify element with 8 neutrons and mass number 14

Mass number = number of protons+number of neutrons. So number of protons = 14 - 8 = 6. The element with 6 protons is carbon (C). In a neutral atom, number of electrons = number of protons, so number of electrons for C is 6.

Answer:

Element	# protons	# neutrons	# electrons	Mass Number
N	7	8	7	15
C	6	8	6	14