Elements Basics

Boron, Silicon, Germanium and Arsenic are members of the

• Metals

• Metalloids

• Non-metals

How did Mendeleev arrange the elements?

• alphabetical 

• density

• melting point

• atomic mass

Answer explanation

Mendeleev arranged the elements by increasing atomic mass, which allowed him to identify periodic trends and predict the properties of undiscovered elements. This method was foundational in the development of the periodic table.

^{What does the 6 represent above the C}

• Symbol 

• Name 

• Mass Number 

• Atomic Number 

Answer explanation

The '6' above the C represents the atomic number, which indicates the number of protons in the nucleus of an atom of carbon. This is a key identifier for the element and distinguishes it from others.

An element is defined by its number of ...

• protons

• electrons

• neutrons

• protons + electrons

Answer explanation

An element is defined by its number of protons, which determines its atomic number and identity. Electrons and neutrons do not define the element itself, as they can vary in isotopes and ions.

What is the atomic mass of Copper?

• 63

• 29

• 34

• 92

Answer explanation

The atomic mass of Copper is approximately 63 atomic mass units (amu). This value is derived from the weighted average of the isotopes of Copper, making 63 the correct choice among the options.

What is the number of protons that the element in this image contain?

• 14

• 7

• 15

• 18

Answer explanation

The element in the image is nitrogen, which has an atomic number of 7. This means it contains 7 protons, making the correct answer 7.

Tags

NGSS.MS-PS1-1

What is the atomic number of this atom?

• 2

• 4

• 6

• none of the above

Answer explanation

The atomic number of an atom is defined as the number of protons in its nucleus. The atom with atomic number 2 is helium, which has 2 protons. Therefore, the correct answer is 2.

Tags

NGSS.MS-PS1-1

How many protons does Neptunium have?

• 9

• 93

• 237

• 273

Answer explanation

Neptunium has an atomic number of 93, which means it has 93 protons. This distinguishes it from other elements, making 93 the correct answer.

How many protons does Argon have?

• 8

• 18

• 39

• 40

Answer explanation

Argon has an atomic number of 18, which means it has 18 protons in its nucleus. This is the defining characteristic of the element Argon.

Tags

NGSS.MS-PS1-1

What is the element symbol on this block?

• Au

• Gold

Answer explanation

The element symbol for gold is 'Au', derived from its Latin name 'Aurum'. Therefore, the correct answer is 'Au'.