Chemistry STAAR Review

How many valence electrons are in an atom of each element in Group 15 in the periodic table?

(a)  

Four students were asked to complete a table for a science assignment. Each student selected one chemical element from each of four groups in the periodic table and then classified each element as a metal, a nonmetal, or a metalloid. Which table was completed correctly?

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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.

Which of the following is an example of a chemical reaction?

• A marshmallow turning black when heated over a fire
• A powder dissolving in water to make lemonade
• An ice cube melting into a puddle of water
• Salt crystals being crushed into a powder
  

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How many Magnesium atoms are in 10MgCl₂?

• 10
• 5
• 20

Tags

NGSS.MS-PS1-1

How many neutrons does the an element with an atomic number of 3 and a mass of 6.9 contain?

(a)  

Tags

NGSS.MS-PS1-1

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

• The neutrons are inside the nucleus and have a positive charge.

• The neutrons are outside the nucleus and have a neutral charge.

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

• The neutrons are inside the nucleus and have a neutral charge.

 What is the mass number of this element?

Mathematical Equivalence

ON

Tags

NGSS.MS-PS1-1

How many electrons are in this element?

• 39

• 19

• 20

• 21

Tags

NGSS.MS-PS1-1

What are the vertical columns on the periodic called?

• groups

• periods

• nonmetals

• metals

• metalloids