The identifying characteristic of an element is its number of

• protons

• neutrons

• electrons

• orbitals

Which type of matter has the furthest distance between the particles?

• solids

• liquids

• gases

• plasma

The state of matter with the closest distance between particles is

• solids

• liquids

• gases

• plasma

Tags

NGSS.MS-PS1-4

When an atom gains or loses neutrons, it becomes

• more stable

• an isotope

• an ion

• less charged

A model of an atom includes red marbles for electrons, green marbles for protons, and blue marbles for neutrons. All marbles have a radius of 2 cm. How could the model be changed to represent the atom more accurately?

• by using smaller marbles to represent electrons

• by using two marbles to represent each neutron

• by using two differently colored marbles for protons

• by switching the colors of the marbles

Tags

NGSS.MS-PS1-1

Which statement explains why most of the mass of an atom is contained in the relatively small nucleus?

• Atoms are composed of less dense subunits than the nucleus

• Protons and neutrons have more mass than electrons

• The nucleus is located at the center of an atom

• Atoms are composed of mostly empty space

Which of these describes a chemical property?

• Color

• Hardness

• Reactivity with acid

• Magnetism

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Where on the periodic table are the metals located?

• Left side

• Middle

• Right side

Where on the periodic table are the nonmetals located?

• Left side

• Middle

• Right side

The element sodium (Na) has an atomic number of 11 and a mass of 23.0 amu. Which element is most likely to have similar characteristics as sodium?

• Neon (Ne), which has a similar symbol

• Magnesium (Mg), which has an atomic mass of 24.3 amu

• Aluminum (Al), which is in the same period on the table

• Potassium (K), which is in the same group on the table