Which of the following steps will slow down the reaction between coal and oxygen?

• Increase the temperature of coal

• Keep the coal in a wide dish

• Keep the coal in a narrow test tube

• Decrease the temperature of oxygen

What is the center of the atom called?

• Electron

• Neutron

• Nucleus

• Proton

Which of the following elements has properties different than the rest?

• K

• Na

• Mg

• S

Read the list of elements given below:

He, Ne, Ar, Kr

Which of the following about the elements is true?

• All of them are unreactive gases.

• All of them are reactive metalloids

• He and Ne are unreactive gases and Ar and Kr reactive metalloids

• He and Ne are unreactive gases and Ar and Kr reactive metalloids

What do atoms consist of?

• Elements

• Compounds

• Charged and uncharged particles

• Neutrons moving around a nucleus

Two different sub-atomic particles are described below: Particle X: Carries a negative charge Particle Y: Attracts Particle X Which statement is true?

• X is a neutron and Y is an electron.

• X is a neutron and Y is a proton.

• X is a proton and Y is an electron.

• X is an electron and Y is a proton.

Which of the following indicates that an endothermic reaction has occurred?

• Heat is released

• Water is formed

• Salt is produced

• Temperature decreases

Two different sub-atomic particles are described below: Particle X: No charge Particle Y: Outside the nucleus Which statement is true?

• X is a neutron and Y is an electron.

• X is a neutron and Y is a proton.

• X is a proton and Y is an electron.

• X is an electron and Y is a proton.

Which of the following elements has properties different than the rest?

• K

• Na

• Mg

• S

Which of the following is a compound?

• Ne

• N2

• NaCl

• O2