Atoms and Elements Review

Who is known as the "father of modern chemistry” because he first organized all known elements into four different groups?

• Johann Wolfgang Döbereiner

• Antoine Lavoisier

• Dmitri Mendeleev

• Henry Moseley

The elements in group 17 of the periodic table are all called halogens. All halogens have the same

• atomic number

• atomic mass

• number of possible isotopes

• number of valence electrons

While looking at xenon (Xe) on the periodic table, a student needs to find an element with a smaller atomic mass in the same group. Where should the student look?

• directly up

• directly down

• directly to the left

• directly to the right

The arrow is pointing to sodium's

• number of neutrons.

• number of valence electrons.

• combined number of neutrons and protons.

• combined number of electrons and protons

Tags

NGSS.MS-PS1-1

All atoms of the same element must have the same number of

• protons

• neutrons

• compounds

• electrons

An atom of the element zinc has an atomic number of 30 and a mass number of 65. How many protons does an uncharged zinc atom have?

• 30

• 35

• 65

• 95

Tags

NGSS.MS-PS1-1

entists in a lab are working with two different samples of the element mercury. They know that the different samples are different isotopes.

Which property of the isotopes must be different?

• the atomic number

• the electric charge

• the element name

• the mass number

Tags

NGSS.HS-PS1-8

When an atom that has no charge loses two electrons, it becomes a

• positive ion.

• negative ion.

• positive isotope.

• negative isotope.

What are the two parts of an atom?

• the nucleus and the proton cloud

• the neutron and the electron cloud

• the neutron and the proton cloud

• the nucleus and the electron cloud

Which argument best explains the charge of an atomic nucleus?

• An atomic nucleus is positively charged because it is composed of neutrons.

• An atomic nucleus is positively charged because it is composed of protons.

• An atomic nucleus is negatively charged because it is composed of electrons.

• An atomic nucleus is negatively charged because it is composed of neutrons.