Matter and Molecules

An element is determined by its number of ______________.

• protons

• neutrons

• protons and neutrons

• protons, neutrons and electrons

Tags

NGSS.MS-PS1-1

Changing the number of protons in an atom changes the ____________.

I. mass

II. element

III. charge of the nucleus

IV. atomic number

• I and III only

• I, II and III only

• II, III and IV only

• All of the above

Tags

NGSS.HS-PS1-8

A volume of oxygen gas, O₂, is heavier than hydrogen gas, H_2, of the same volume because ________________.

• each proton and neutron in oxygen atoms are heavier than that in hydrogen atoms

• oxygen molecules have stronger bonds than hydrogen molecules

• there are more protons and neutrons in each oxygen atom compared to hydrogen atom

• oxygen is a diatomic molecule while hydrogen is a monoatomic molecule

Tags

NGSS.MS-PS1-1

In the following diagram, each sphere represents either an Element X atom or an Element Y atom. What is a likely chemical formula for this substance?

• XY

• X₄Y

• XY₄

• X₅Y₂₀

Tags

NGSS.MS-PS1-1

According to the atomic model, electrons are usually found ______________.

• in the nucleus

• attached to the nucleus

• outside the nucleus

• attached to the proton

Which of the following chemical formulae is a compound?

• Xe

• Cl

• Na

• KF

Tags

NGSS.MS-PS1-1

How many hydrogen atoms are there in a molecule of (NH₄)₂Cr₂O₇?

• 2

• 4

• 6

• 8

Tags

NGSS.MS-PS1-1

The three basic constituents of an atom are _____________________.

• electrons, neutrons and protons

• ions, neutrons and protons

• electrons, nucleus and protons

• electrons, neutrons and photons

Tags

NGSS.MS-PS1-1

An atom is electrically _____________ because ___________________________.

• neutral; there is a neutral nucleus in the middle of an atom

• neutral; there are negatively charged electrons moving around a positively charged nucleus

• positive; there is a large positive nucleus surrounded by small negatively charged electrons

• negative; there are many small negatively charged electrons

Tom constructed a model of an atom using pieces of different coloured clay. Which of the following diagrams represents an accurate model of an atom?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-1