2nd Quarter Review (Grade 6)

The plum pudding atomic model introduced the presence of scattered negatively charged

   particles isolated in a positive sphere. Which concept of Thomson’s model and theory was later  

   revised?

• The atoms are indivisible

• The absence of the nucleus

• The existence of the neutral particles

• The distribution of electrons in a fixed orbit

You observed that chlorine has an atomic mass of 37 and an atomic number of 17. How many neutrons does chlorine have?

• 17

• 37

• 18

• 20

Why do atoms with the same number of protons and electrons behave as the same element?

• Because they all have the same mass.

• Because protons give the same characteristics.

• Because they all have the same color and shape.

• Because the number of protons tells what element they are. 

What characteristics of a colloid make milk different from a suspension?

• Milk mixture has no visible particles.

• Milk components separate into layers over time.

• Milk particles are dissolved and distributed evenly.

• Milk particles are equally distributed without any residue settling.

What will happen if you put more sugar in a saturated saltwater solution?

• The added solute will still be dissolved

• The added sugar will change the composition of the mixture.

• The added sugar will affect the temperature of the solution.

•   The added sugar will settle at the bottom as the saturated solution can no longer dissolve more solute.

Farah wanted to separate fine sand from gravel to mix with cement. Which separation method would be best for this task?

• Distillation

• Decantation

• Sieving

• Magnet

An atom has 12 protons and 12 neutrons in its nucleus and 12 electrons

    orbiting around it. What is the atomic number of this atom?

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• 12

• 11

• 13

• 10

Samantha holds a block of metal with a mass of 200 grams which then she dropped into a container with a volume of 50 cm³, what is its density?

• 4 g/cm³

• 10 g/cm³

• 5 g/cm³

• 0.25 g/cm³

Why is separating the components of a colloidal mixture more difficult than separating the components of other mixtures?

• Particles of colloids are larger than suspension.

• Particles of colloids are smaller and remain dispersed evenly.

• Particles of a colloid are smaller and settle at the bottom forming layers.

• Colloidal particles are the same as homogeneous mixtures making it difficult to separate.

If the atomic number of an element is 7 and its mass number is 15, what can you infer about the atom’s structure?

• The atoms have 7 protons, 8 neutrons, and 7 electrons

• The atoms have 7 protons, 7 neutrons, and 8 electrons

• The atom has 8 protons, 7 neutrons, and 7 electrons

• The atoms have 15 protons, 7 neutrons, and 7 electrons