Savvas Chem

A scientist made the following contributions in the development of the Periodic Table.

• Johan W. Dobereiner

• John Newlands

• Lothar Meyer

• Dmitri Mendeleev

Tags

NGSS.HS-PS1-1

Element M is placed in Group 14 and Period 3 of the Periodic Table. What is the electron arrangement of an atom M?

• 2.3

• 2.4

• 2.8.3

• 2.8.4

Tags

NGSS.HS-PS1-1

• M, G, J, L

• G, M, L, J

• G, J, L, M

• M, L, J, G

Tags

NGSS.HS-PS1-1

Table 2 shows the relative atomic masses and number of neutrons for the elements G and J. G and J are not the actual symbols of the elements.

Which of the following statements are true about these elements?

I Element G is more reactive than element J.

II Atoms G and J have two valence electrons.

III Elements G and J are in the same group in the Periodic Table.

IV Elements G and J can conduct electricity.

• I and II

• I and III

• II and IV

• III and IV

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

An atom Y with nucleon number of 23 has 12 neutrons. Which element has the same chemical properties as element Y?

[Proton number: B = 5, Mg = 12, Cl = 17, K = 19]

• Boron

• Magnesium

• Chlorine

• Potassium

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Neon gas is used to provide an inert atmosphere for welding. Which of the following explains this property of neon?

• It has a stable electron

  arrangement

• It is placed in Group 18 of the

  Periodic Table

• It exists as monoatomic gas

• It has low melting and boiling

  points

Tags

NGSS.HS-PS1-1

Element R is located in the same group as lithium in the Periodic Table of Element. Which of the following are the properties of R?

• Diatomic particle

• Reacts vigorously with water

• Cannot conduct electricity

• High melting and boiling points

Tags

NGSS.HS-PS1-1

An atom of element T has an electron arrangement of 2.8.8.1. An atom of element W has 4 neutrons and relative atomic mass of 7. Which of the following statements is true about elements T and W?

• Element W is more reactive than element T.

• Melting point of element W is lower than element T.

• Reaction of element W with water is less vigorous than that of element T.

• Density of element W is higher than that of element T.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Element G, J, and L are located in Group 17 of the Periodic Table. Atomic radius of element J is the smallest. In an experiment, when vapour L is passed over hot iron wool, the iron wool glows brightly. When vapour G is passed over hot iron wool, the iron wool glows dimly. The reactivity of elements G, J, and L in ascending order is ...

• L, G, J

• G, L, J

• G, J, L

• J, L, G

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Table 3 shows the nucleon number and number of neutrons for elements W, X, Y and Z.

• W

• X

• Y

• Z

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2