Category 1 STAAR

Which statement correctly describes the location and charge of the electrons in an atom?

• The electrons are inside the nucleus and have no charge.

• The electrons are outside the nucleus and have no charge.

• The electrons are inside the nucleus and have a negative charge.

• The electrons are outside the nucleus and have a negative charge.

What type of particles are found in the cloud surrounding the atom's nucleus?

• Positively charges particles and negatively charges particles

• Negatively charged particles only

• Neutral particles and positively charges particles

• Positively charges particles only

Tags

NGSS.MS-PS1-1

Which of the following best describes an electron?

• It has no charge and about the same mass as a proton.

• It has a negative charge and much less mass than a proton.

• It has a positive charge and much more mass than a neutron.

• It has a negative charge and about the same mass as a neutron.

Tags

NGSS.MS-PS2-3

A chemist is identifying elements present in a sample of seawater. What characteristics of an element's atoms always determines the element's identity?

• The number of protons

• The number of neutrons

• The location of the valence electrons

• The number of valence electrons

A student is studying calcium, a highly reactive element that humans need for strong bones. Which characteristic of calcium is most closely related to its chemical reactivity?

• The 20 protons in each atom of calcium

• The density of calcium, which is 1.54 g/cm³

• The atomic mass of calcium, which is 40.078 amu

• The 2 valence electrons in each atom of calcium

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The table below lists three characteristics of an atom of an element.

An atom of which element is described by the data in the table?

• Radon (Rn)

• Cadmium (Cd)

• Rubidium (Rb)

• Astatine (At)

Tags

NGSS.MS-PS1-1

A model of an atom is shown below.

An atom or which element is represented by this model?

• Boron (B)

• Carbon (C)

• Neon (Ne)

• Sodium (Na)

Tags

NGSS.MS-PS1-1

When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with?

• The total number of neutrons in the unknown element

• The total number of particles in the nucleus of the unknown element

• The number of protons in the nucleus of the unknown element

• The number of valence electrons in the unknown element

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Students were asked to identify the location of elements in the periodic table based on clues printed on game cards.

Based on the data, which periodic table shows the correct location of the four elements?

• 
• 
• 
• 

Which pair of properties describes the elements in Group 18?

• They are chemically stable and liquid at room temperature.

• They have eight valence electrons and are flammable.

• They are magnetic and boil at low temperature.

• They are gaseous at room temperature and chemically stable.