$CATEGORY: Science - Khan Academy/5.Periodic Classification of Elements/5.Periodic Classification of Elements--Making Order Out of Chaos-The Modern Periodic Table

//Multiple Choice

The valency of elements in Group 1 is\:
{
  = 1
  ~ 2
  ~ 3
  ~ 0
}

The valency of elements in Group 17 is\:
{
  = 1
  ~ 2
  ~ 3
  ~ 7
}

The valency of an element in Group 2 is\:
{
  ~ 1
  = 2
  ~ 3
  ~ 0
}

As we move across a period from left to right, the valency of elements generally\:
{
  = Increases
  ~ Decreases
  ~ Remains the same
  ~ Becomes zero
}

The valency of noble gases is\:
{
  ~ 1
  = 0
  ~ 2
  ~ 7
}

The valency of oxygen (Group 16) is\:
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

Which of the following elements has a valency of 3?
{
  = Nitrogen
  ~ Oxygen
  ~ Fluorine
  ~ Neon
}

The valency of elements in Group 13 is\:
{
  ~ 1
  ~ 2
  = 3
  ~ 4
}

As you move down a group, the valency of elements\:
{
  ~ Increases
  ~ Decreases
  = Remains the same
  ~ Becomes zero
}

The element with atomic number 15 (Group 15) has a valency of\:
{
  ~ 1
  ~ 2
  = 3
  ~ 4
}

//True or False

The valency of Group 1 elements is always 1. {T}

The valency of Group 2 elements is always 3. {F}

The valency of Group 18 elements is 0. {T}

The valency of elements increases as we move across a period from left to right. {T}

The valency of an element in Group 17 is 7. {F}

The valency of elements in Group 16 is 2. {T}

As we move down a group, the valency of elements increases. {F}

The valency of nitrogen is 3. {T}

The valency of sodium is 2. {F}

The valency of an element is determined by the number of protons in its nucleus. {F}

//Fill in the blanks

The valency of elements in Group 1 is always ______.
{
  = 1
  ~ 2
  ~ 3
  ~ 0
}

The valency of an element in Group 17 is ______.
{
  = 1
  ~ 2
  ~ 3
  ~ 7
}

The valency of elements in Group 2 is ______.
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

The valency of elements in Group 18 is ______.
{
  = 0
  ~ 1
  ~ 2
  ~ 3
}

As we move from left to right across a period, the valency of elements generally ______.
{
  = Increases
  ~ Decreases
  ~ Remains the same
  ~ Becomes zero
}

The valency of oxygen is ______.
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

The valency of nitrogen (Group 15) is ______.
{
  ~ 1
  ~ 2
  = 3
  ~ 4
}

The valency of carbon (Group 14) is ______.
{
  ~ 1
  ~ 2
  ~ 3
  = 4
}

The valency of an element in Group 3 is ______.
{
  ~ 1
  ~ 2
  = 3
  ~ 4
}

The valency of sodium (Na) is ______.
{
  = 1
  ~ 2
  ~ 3
  ~ 0
}

//Numericals

The atomic number of an element is 7 (Group 15) has how many valence electrons?
{
  = 5
  ~ 6
  ~ 7
  ~ 8
}

An element has atomic number 12. How many valence electrons does it have?
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

The atomic number of an element is 16. What is its valency?
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

The atomic number of an element is 19. What is its valency?
{
  = 1
  ~ 2
  ~ 3
  ~ 4
}

The atomic number of an element is 14. How many valence electrons does it have?
{
  = 4
  ~ 5
  ~ 6
  ~ 2
}

The atomic number of an element is 9. What is its valency?
{
  = 1
  ~ 2
  ~ 3
  ~ 0
}

An element in Period 3 and Group 17 has an atomic number of 17. What is its valency?
{
  = 1
  ~ 2
  ~ 3
  ~ 7
}

An element has atomic number 20. How many valence electrons does it have?
{
  ~ 1
  = 2
  ~ 3
  ~ 4
}

The atomic number of an element is 13. What is its valency?
{
  ~ 1
  ~ 2
  = 3
  ~ 4
}

The atomic number of an element is 17. What is its valency?
{
  = 1
  ~ 2
  ~ 3
  ~ 7
}

//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
= Group 1 elements -> Valency \= 1
= Group 2 elements -> Valency \= 2
= Group 17 elements -> Valency \= 1
= Group 18 elements -> Valency \= 0
}


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