What property do the following elements have in common?
li, c, and f

They all belong in the same period, thus they have the same energy levels which is 2.

In the periodic table, elements are categorized by group and period. Periods are arranged in rows. Below is a picture of the periodic table and where these elements are.

As you can see, they all belong in the same period (row). Elements in the same period have the same number of atomic orbitals, or in other words, they have the same electron energy level. The period number tells you the energy level. Lithium (Li), Carbon (C), and Fluorine (F) are in period 2, so they all have two energy levels.

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

question: ray weighs 100 kilograms, his wrestling partner, bobby, weighs 50 kilograms. if ray moves at 4 m s , how fast will bobby have to run at him to apply an equal amount of kinetic energy?

answer: 8 m/s he needs to run twice as fast to keep up so he has some work to do

explanation:   if the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

question answered by

(jacemorris04)