Which one of the following is the electron arrangement of the strongest reducing agent?

• 1s² 2s² 2p⁵

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3s² 3p⁵

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Molecules with a permanent dipole include

1 NH₃

2 PCl₃

3 SCl₂

4 SiCl₄

• 1, 2 and 3 only are correct.

• 1 and 3 only are correct.

• 2 and 4 only are correct.

• 4 only is correct.

The percentage by mass of the elements in a compound is

C=72%, H=12%, O=16%.

What is the mole ratio of C : H in the empirical formula of this compound?

• 1:1

• 1:2

• 1:6

• 6:1

Based on electronegativity values, which bond is the most polar?

• B⎼C

• C⎼O

• N⎼O

• O⎼F

Which of the quantities in the enthalpy level diagram below is (are) affected by the use of a catalyst?

• I only

• III only

• I and II only

• II and III only

Tags

NGSS.HS-PS1-4

Which statement about neighbouring members of all homologous series is correct?

• They have the same empirical formula.

• They differ by a CH₂ group.

• They possess different functional groups.

• They differ in their degree of unsaturation.

A compound contains 40.00% carbon, 6.73% hydrogen and 53.27% oxygen by mass. Determine the empirical formula.

• CHO

• CH₂O

• CH₂O₂

• CHO₂

What is the symbol for an alpha particle?

• ⁴₂He
• ⁰_-1e
• ⁰₊₁ e
• ¹₀n

Tags

NGSS.HS-PS1-8

In the symbol ²⁰⁶₈₂Pb what does 206 stand for?

• Mass number
• Atomic number
• Atomic mass
• Number of protons

Balance the following equation:
¹⁴₆C --> ⁰_-1e + ________

• ¹⁴₅B
• ¹⁴₆C
• ¹⁴₇N
• ⁴₂He

Tags

NGSS.HS-PS1-8