1.
Sana’a buys a ring made of gold and silver. After few weeks, the silver part of the ring looks black and dull. The gold part stays shiny, the problem is:
Correct Answer
C. What changes happened to the silver part?
2.
Leen puts some ice cubes in a glass of water. She leaves her glass on the table. When she returns, the ice is gone. The problem is:
Correct Answer
A. What happened to the ice cubes?
3.
Omar used a graduated cylinder to measure 40 ml of water, then after freezing the water over night the volume of the water raised to 44 ml. the problem is:
Correct Answer
A. How does freezing affect the volume of water?
Explanation
Freezing water causes it to expand, which is why the volume of the water increased from 40 ml to 44 ml. When water freezes, its molecules arrange themselves in a hexagonal lattice structure, which takes up more space than when the molecules are in a liquid state. Therefore, freezing water increases its volume.
4.
Kareem uses a balance to measure the mass of an apple. He then cut up the apple into four pieces of varying sizes. He wanted to know if the size of the apple pieces affects its total mass or not? His hypothesis is:
Correct Answer
B. If the size of the apple pieces changes, then its total mass will not change.
Explanation
The correct answer suggests that Kareem's hypothesis is incorrect. According to the answer, if Kareem changes the size of the apple pieces, the total mass of the apple will not change. This implies that the size of the apple pieces does not affect its total mass.
5.
In the science lab Farah was measuring the melting point and the boiling point of water, she organized her results in the following line graph that shows the relation between the temperature and the time. She needs to set her experiment and test when does ice change to liquid water, her hypothesis will be:
Correct Answer
A. If the temperature increases, then ice will change to liquid water.
Explanation
The correct answer is "If the temperature increases, then ice will change to liquid water." This hypothesis is based on the understanding that ice melts and changes into liquid water when the temperature rises above its melting point. The line graph provided in the question shows a positive correlation between temperature and time, indicating that as the temperature increases, the time taken for ice to change into liquid water decreases. Therefore, it can be inferred that increasing temperature leads to the change from ice to liquid water.
6.
In parallel circuit, electricity has more than one path to flow. Electrical current can flow in different paths as they flow from the negative side of the battery to the positive side. Hamzeh wanted to know if a broken or a missing light bulb affects the other light bulb or not. His hypothesis will be:
Correct Answer
A. If a light bulb is missing or broken, then the other light bulb will light.
Explanation
If a light bulb is missing or broken, then the other light bulb will light. In a parallel circuit, each component is connected separately to the power source, so if one light bulb is missing or broken, the other light bulb will still receive electricity and light up.
7.
A scientist wants to build a series circuit using a small battery and a small light bulb, he runs out of wire. What everyday object could he use to connect the battery to the light bulb?
Correct Answer
A. Use a metallic spoon
Explanation
A metallic spoon can be used to connect the battery to the light bulb because metal is a good conductor of electricity. When the spoon is connected to the positive and negative terminals of the battery, it allows the flow of electrons from the battery to the light bulb, completing the circuit. This enables the electrical energy from the battery to power the light bulb and produce light. Plastic ruler and rubber eraser are not good conductors of electricity, so they would not be able to effectively transmit the electrical current between the battery and the light bulb.
8.
If you find a metal bar, how can you determine if it is a magnet or not?
Correct Answer
B. Put something made of iron near it and see the reaction
Explanation
By putting something made of iron near the metal bar and observing the reaction, we can determine if it is a magnet or not. If the metal bar is a magnet, it will attract the iron object. However, if it is not a magnet, there will be no attraction or reaction between the two objects.
9.
Zaid wanted to differentiate between the chemical and the physical change, Study the experiment below. How can you tell Zaid if a change has occurred?
Correct Answer
A. Mix vinegar and baking soda
Explanation
When vinegar and baking soda are mixed together, a chemical reaction occurs. This can be observed by the fizzing and bubbling that takes place, as well as the release of carbon dioxide gas. In contrast, when vinegar is mixed with water or water is mixed with baking soda, no such reaction occurs. Therefore, the occurrence of a chemical reaction, as evidenced by the fizzing and bubbling, can be used to determine if a change has occurred.
10.
Layal washes dishes and put the clean wet dishes on a drying rack. Water in these dishes dries up because:
Correct Answer
C. The water evaporates.
Explanation
The correct answer is "The water evaporates." When Layal washes the dishes and puts them on the drying rack, the water on the dishes is exposed to the air. Over time, the water molecules gain enough energy from the surrounding air to break free from the liquid and turn into gas. This process is called evaporation. As a result, the water on the dishes dries up.
11.
An astronaut weighs on Earth 180 pound, while on the moon he weighs about 30 pound. This is due to:
Correct Answer
A. The gravity on the moon is less than the gravity on Earth.
Explanation
The astronaut weighs less on the moon compared to Earth because the gravity on the moon is less than the gravity on Earth.
12.
Mohammad uses the graph below to find the relation between the power of the electromagnet and the number of coils. He finds out that:
Correct Answer
B. The strength of the electromagnet increases when the number of coils increases.
Explanation
According to the given information, Mohammad uses the graph to find the relation between the power of the electromagnet and the number of coils. He finds out that the strength of the electromagnet increases when the number of coils increases. This means that there is a positive correlation between the number of coils and the strength of the electromagnet. As the number of coils increases, the power of the electromagnet also increases.
13.
An electrician is a person who works on and repairs electrical equipment. He needs to protect himself from an electric shock. So he uses: rubber gloves, special shoes with thick rubber soles, and plastic tools. Which all are:
Correct Answer
A. Insulators to keep him safe.
Explanation
The electrician uses rubber gloves, special shoes with thick rubber soles, and plastic tools, all of which are insulators. Insulators are materials that do not allow electricity to flow through them easily. By using these insulating materials, the electrician can protect himself from electric shock by preventing the flow of electricity through his body.
14.
Electricity and magnetism are closely related. They have a great role in our everyday live than we might realize. Wind turbines generate electricity. Water turbines generate electricity too. All generators transform energy from:
Correct Answer
C. Kinetic into electrical energy.
Explanation
Electricity and magnetism are closely related as they are both forms of energy. Wind turbines and water turbines are examples of generators that transform energy. In this case, the correct answer is "Kinetic into electrical energy." This means that the turbines convert the kinetic energy of the wind or water into electrical energy.
15.
Raed connected this circuit. He tried to add or remove parts to make a brighter light. When he added more batteries, the circuit made a brighter light, but when he added less batteries he made a dim light, finally he generalized that
Correct Answer
B. Adding more batteries makes brighter light.
Explanation
The correct answer is "Adding more batteries makes brighter light." This conclusion can be drawn from the given information that when Raed added more batteries to the circuit, the light became brighter. This suggests that the additional batteries increased the current flowing through the circuit, resulting in a brighter light. The other statements, such as adding more light bulbs or removing batteries, are not supported by the given information and cannot be generalized based on Raed's experiment.