When do atoms combine to form a compound?

• when the elements are different

• when the elements are the same

• when the compound is less stable

• when the compound is more stable

Tags

NGSS.MS-PS1-1

What shows the elements a compound contains and the exact number of the atoms of each element in a unit of that compound?

• the periodic table

• a dot diagram

• the activity series

• a chemical formula

What is the total number of atoms in the compound Ca(ClO₃)₂?

• 9

• 2

• 3

• 6

Tags

NGSS.MS-PS1-1

What are dot diagrams used to represent?

• the structure of the nucleus

• protons

• outer electrons

• atomic mass

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following elements has the simplest electron dot diagram?

• Hydrogen

• Helium

• Lithium

• Beryllium

Tags

NGSS.HS-PS1-1

What will the A atom do to become more stable?

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What will the B atom do to become more stable?

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The chemical formula for table salt is NaCl. Which element has more atoms in the formula? Which element has a larger share of the mass in the formula?

Tags

NGSS.MS-PS1-1

Covalent bonds are generally formed between what sort of elements?

• ones that form ions easily

• a metal and a nonmetal

• metals

• nonmetals

A lithium atom has three protons and three electrons. A fluoride atom has nine protons and nine electrons, with seven electrons in its outer energy level. Using a dot diagram of the two atoms, what type of bond forms between the lithium atom and the fluoride atom and why?

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2