Who was the first person out of the following to create the concept of an atom?

Who determined that most of an atom is empty space?

What do the groups on the periodic table represent?

(Multiple answers)

If the group number is 18 how many valence electrons are there?

Who found neutrons?

Who created the "plum pudding model"?

Describe electrons?

Describe neutrons.

Describe protons.

What are valence electrons?

An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abundance with 21.99 amu. Calculate the average atomic mass of this element.

Average atomic masses listed by IUPAC are based on a study of experimental results. Bromine has two isotopes, ⁷⁹Br and ⁸¹Br, whose masses (78.9183 and 80.9163 amu) and abundances (50.69% and 49.31%) were determined in earlier experiments. Calculate the average atomic mass of Br based on these experiments.

How many valence electrons does helium have?

How many electrons are in the 4th ring of an atom?

How many electrons are in the first ring of an atom?

What is on the outside of the Lewis Dot structure?

How many valence electrons are in the following sequence?

[1s² 2s² 2p⁶ 3s² 3p⁴]

How many valence electrons are in the following sequence?

[1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸]

I have 11 neutrons, a mass of 24, have a charge of +1, how many electrons do I have.

I am a noble gas with only 1 electron and have a charge of -1, who am I?

I am very reactive and i am in the second row, who am I?

True of False: Mixtures can be made out of mixtures of atoms.

Which of the following are elements?