S8P1E

Compare the electron configurations of elements in the same period.

• They have the same number of electrons.

• They have the same number of electron shells.

• They have the same number of valence electrons.

• They have the same atomic number.

Elijah is trying to understand how electrons are arranged in an atom. Can you help him construct a simple model to explain this arrangement?

• Electrons are arranged randomly around the nucleus.

• Electrons are arranged in fixed orbits around the nucleus.

• Electrons are arranged in a cloud around the nucleus.

• Electrons are arranged in a single line around the nucleus.

What does the nucleus of an atom contain?

• protons and electrons

• neutrons and positrons

• protons and neutrons

• electrons and neutrons

Which statement BEST describes ammonia, NH₃?

• It is an atom that contains one molecule of nitrogen and three molecules of hydrogen.

• It is a molecule that contains one atom of nitrogen and three atoms of hydrogen

• It is a molecule that contains three atoms of nitrogen and one atom of hydrogen.

• It is an atom that contains three molecules of nitrogen and one molecule of hydrogen.

Tags

NGSS.MS-PS1-1

What is the smallest unit of matter that retains the chemical properties of the element to which it belongs?

• a nucleus

• an electron

• an atom

• a molecule

How many valence electrons does Aluminum have?

• 1

• 2

• 5

• 3

Marcus discovered that sodium (Na) is found in Group 1, Period 3 on the periodic table. Where should Marcus look to find another element that has similar properties to those of sodium?

• in Group 1

• on the opposite side of the periodic table

• in Period 3

• 
  at elements whose symbols begin with the letter N

Which of these is NOT an example of a molecule?

• CO₂

• He

• NH₃

• CaCO₃

Tags

NGSS.MS-PS1-1

Which element does this Bohr model represent?

• Cobalt

• Magnesium

• Sodium

• Carbon

Tags

NGSS.MS-PS1-1

Where are electrons located in an Atom?

• inside the neucleus

• surrounding the nucleus in the electron cloud

• with the protons

• with the neutrons