CSA REVIEW #2

Gaining or losing electrons makes an atom—

• an ion

• covalent

• bonded

• positively charged

Tags

NGSS.MS-PS1-5

Of the elements shown here, which element has the greatest atomic mass?

• Lithium

• Sodium

• Magnesium

• Scandium

1. Which of the following best represents our current understanding of atomic structure?

• nuclear model

• Bohr model

• solid sphere model

• electron cloud model

1. Why do elements in the same group on the periodic table share many physical and chemical properties?

• 1. They have the same atomic mass.

• 1. When combined with oxygen and hydrogen, they always give off water vapor.

• They contain the same number of electrons in their outer energy level.

• They have the same boiling point.

Based on this picture, which of the following is true?

• 1. Atoms and their isotopes have the same mass.

• 1. Carbon-12 represents the atom and Carbon-13 and Carbon-14 are isotopes.

• 1. Whether an atom is an isotope depends on the number of protons in its nucleus. 

• 1. Carbon-12 is heavier than Carbon-13 and Carbon-14.

Tags

NGSS.MS-PS1-1

Why do atoms gain, lose or share electrons?

• To increase the number of valence electrons

• To become metals

• To generate electricity

• To become chemically stable

Tags

NGSS.MS-PS2-3

1. The law of conservation of matter (mass) states that regardless of how substances within a closed system are changed—

• 1. Electrons will form ionic bonds

• The mass will be equal in physical changes but not chemical changes

• 1. Isotopes will have weigh the same as their elements

• 1. The total mass remains the same

Tags

NGSS.MS-PS1-5

Which of the following should go in the blank to make the chemical equation true?

• 4

• 3

• 2

• 6

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Use this chemical equation to answer the question.

2HCl + 2Na -------  2NACl + H₂

​ (a)   ​ (b)   ​ ​ (c)  

• reactants
• yeild or change
• products

Answer explanation

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following best explains what happens when hydrogen and carbon combine?

• 1. No chemical changes take place.

• 1. Both hydrogen and carbon lose electrons.

• 1. Four ionic bonds form.

• 1. Four covalent bonds form.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2