Chem Practice Regents MC 7106

Which statement describes the structure of an atom?

• The nucleus contains positively charged electrons.

• The nucleus contains negatively charged protons.

• The nucleus has a positive charge and is surrounded by negatively charged electrons.

• The nucleus has a negative charge and is surrounded by positively charged electrons.

Tags

NGSS.HS-PS1-8

Which term is defined as the region in an atom where an electron is most likely to be located?

• nucleus

• orbital

• quanta

• spectra

What is the number of electrons in an atom of scandium?

• 21

• 24

• 45

• 66

Tags

NGSS.HS-PS1-1

Which particle has the least mass?

• a proton

• an electron

• a helium atom

• a hydrogen atom

Which electron transition in an excited atom results in a release of energy?

• first shell to the third shell

• second shell to the fourth shell

• third shell to the fourth shell

• fourth shell to the second shell

On the Periodic Table, the number of protons in an atom of an element is indicated by its

• atomic mass

• atomic number

• selected oxidation states

• number of valence electrons

Which type of formula shows an element symbol for each atom and a line for each bond between atoms?

• ionic

• structural

• empirical

• molecular

What is conserved during all chemical reactions?

• charge

• density

• vapor pressure

• melting point

Tags

NGSS.HS-PS1-7

In which type of reaction can two compounds exchange ions to form two different compounds?

• synthesis

• decomposition

• single replacement

• double replacement

At STP, two 5.0-gram solid samples of different ionic compounds have the same density. These solid samples could be differentiated by their

• mass

• volume

• temperature

• solubility in water