Science Pisay Flashcards
Which of the following is an observation?
A. A substance emits smoke because it is hot
B. The chocolate drink tastes bitter
C. Scientists agree that global warming is happening
D. Water is composed of hydrogen and oxygen atoms.
B
Which of the following methods must be used to recover the salt from brine solution
A. Pour the solution through the strainer to remove the salt from the liquid
B. Boil the solution until all liquid has evaporated
C. Transfer the solution to another container using a stirring rod
D. Use a distillation setup to recover the pure solvent
B
An example of a heterogeneous mixture is
A. Brine
B. 70% rubbing alcohol
C. Pollen dust in air
D. Instant coffee in hot water
C
Ramon was assigned to determine whether the colorless liquid is a substance or a solution. He observed that the liquid started to boil at 85°C and continued boiling at 100 °C. Ramon concluded that
A. The liquid is a substance
B. The liquid is a solution
C. The liquid is water
D. The amount of liquid is not enough
B
Which of the following is a quantitative description?
A. In the math class, there are more girls than boys
B. There are thick books on the table
C. There are just enough chairs in the classroom
D. There are two sets of computers in the classroom
D
To be in equilibrium an object
A. Must be accelerating
B. Must have no forces acting on it
C. Must have no unbalanced force acting on it
D. Must have no inertia
C
An object at rest may have
A. Speed
B. Velocity
C. Acceleration
D. Energy
D
A rock sample taken from the moon was analysed by the scientists of NASA. What property of the rock will not be the same in the moon and earth
A. Mass
B. Weight
C. Size
D. Shape
B
A constant force is needed to keep a car moving along a horizontal surface at a uniform velocity. This means that
A. The car has inertia
B. The car has weight
C. The friction forces acting on the car are equal to the force applied
D. The friction acting on the car are less than the force applied
C
A truck starts from rest and moves along a straight road. Every minute its speed increases by 10 meters per minute. This indicates that the truck travels with
A. Decreasing speed
B. Constant acceleration
C. Constant velocity
D. Increasing acceleration
B
Saltwater is denser than freshwater. A person loads up a boat in a freshwater river and sails down the river towards the sea. When the boat reaches the saltwater
A. It will sink deeper into the water
B. It will float a little higher in the water
C. The volume of water displaced by the boat will increase
D. The amount displaced by the boat will remain the same
B
Nikki filled up a 1.0- liter jar with sea shells. Next she filled it with water up to the brim. When she measured the amount that was added she found out that it is 350.0 mL. What does 350.0 mL represent
A. The actual volume of the sea shells
B. The volume of air spaces in the jar
C. The density of the sea shells
D. The volume of the sea shells minus the volume of air spaces
B
It takes a certain amount of time for starlight to travel from the star to the earth. When you look back at the light from the distant stars, you are actually looking back in time. Which of the following statements explains the meaning of this?
A. The star that we see now is the same star at the time of its birth
B. The star that we see now does not exist anymore.
C. The star that we observe now is as it appeared when light was emiited
D. The star that we observe now shows it present properties.
C
If a round ball X were rolled across a smooth floor to collide with a similar ball Y that was stationary, which of the following is most likely to happen?
A. Both balls will gain kinetic energy.
B. Ball X will increase its kinetic energy while ball Y will decrease it
C. The kinetic energy of both balls will remain the same
D. Ball X’s kinetic energy will decrease while ball Y’s will increase
D
Which process results in the release of latent heat?
A. Melting of ice
B. Heating of liquid water
C. Condensation of water vapor
D. Evaporation of water
C
What happens when a stone drops to the ground without friction
A. Its kinetic energy is conserved
B. It’s gravitational potential energy is conserved
C. Its kinetic energy is converted to gravitational potential energy
D. There is no change in it’s total energy
D
Before it can be used, solar energy must be converted to other forms of energy because it is
A. Spread out over a wide area
B. Not available at night
C. Received mostly in the form of light
D. Too hot to handle
A
Joseph was not feeling well. When his mother took his body temperature, it measured 98°. He did not have a fever. What temperature scale were they using
A. Mercury
B. Celsius
C. Fahrenheit
D. Kelvin
C
Which of the following is an endothermic reaction?
A. Cold water turns to steam
B. Iodine gas sublimates
C. Water vapor liquifies
D. CO2 gas becomes dry ice
A
One of the causes of fish kill in a lake is acidic deposition. Which of the following substances could be added to neutralize the lake without harming the fish?
A. Vinegar
B. Table salt
C. Limestone
D. Acetone
C
The frequency of electromagnetic radiation is the number of waves that pass a point in a specific amount of time. If blue light has longer wavelength than violet light, and red light has longer wavelength than blue light which of the three has the highest frequency?
A. Blue light
B. Red light
C. Violet light
D. They have the same frequency
C
Relative humidity is the percentage of moisture the air holds relative to the amount it could hold at a particular temperature. If, at a certain temperature, 1.0 kg of air can hold as much as 12 g of water vapor but is actually holding 9 g of it. The relative humidity of air at that temperature would be (9/12) x 100 = 75%. If 1.0 kg of air can hold 15 g of water vapor but actually holds only 10 g, what is the relative humidity?
A. 67%
B. 57%
C. 15%
D. 25%
B
In which of the following conditions is the net force zero?
A. A body moves at constant speed around a circle.
B. A body moving along a straight line slows down.
C. A body moves at constant speed along a straight line.
D. A freely falling body
C
Photosynthesis is one of the most important chemical reactions performed by nature. Its chemical reactants are
A. glucose and oxygen.
B. carbon dioxide and glucose.
C. carbon dioxide and water.
D. glucose and sunlight.
C
All of the following exhibit chemical changes except:
A. Milk left uncovered curdles.
B. Water droplets form on a cold glass.
C. Green mango turns yellow.
D. The silver earrings tarnish.
B
A powdered material is mixed with water. Particles of yellow solid float on the surface while gray solid particles sink to the bottom. The yellow particles are skimmed off and the liquid is poured off to get the gray particles. The property that explains why the two solids separated is:
A. density.
B. solubility.
C. decantation.
D. filtration.
A
With the very large amount of air pressing on us, our body is not flattened or crushed. This is so because
A. we are surrounded by very light air.
B. our body is supported by strong bones.
C. our body fluids oppose the pressure.
D. the pressure is distributed all over the body.
D
A bag of iron and a bag of chicken feathers were weighed separately. Both were found to have the same weight. This indicates the bags have the same
A. mass.
B. volume.
C. density.
D. size.
A
Which of the following statements describes an intensive property of matter?
A. The height of the tree is 1.8 m.
B. 24 karat gold is very malleable.
C. The boy weighs 43.8 kg.
D. One cup of milk measures 300 mL.
B
In a controlled experiment, a comparison of tests is possible because two sets of tests are
A. identical, but carried out under totally different conditions.
B. identical, except in one set of factors or one condition.
C. identical, but carried out at different times.
D. identical, except in their outcome.
B
Which of the following statements make an observation reliable?
A. It must be a first observation.
B. It is made through the use of an instrument.
C. It reflects the experience of the observer.
D. It is an experience that can be repeated.
D
Potassium is a metallic element that melts at 64°C and boils at 774°C. What is the physical state of the metal at 70°C?
A. Solid
B. Liquid
C. Gas
D. Cannot be determined from the given information.
B
A student wants to find out whether a certain liquid is acidic. Which of the following procedures would tell him whether or not it is so?
A. Determine its boiling point.
B. Taste to find out if it is sour or not.
C. Use the litmus paper test.
D. Add salt and water.
C
Which of the following would happen when an acid is slowly poured to a basic solution?
A. Bubbles would form.
B. The pH of the basic solution would increase.
C. The pH of the acid would increase.
D. The color of the mixture would change.
C
Air is a mixture of different gases, the most abundant of which is
A. Carbon dioxide.
B. Nitrogen.
C. Oxygen.
D. Argon.
B
A molecule of glucose is represented by the formula C₆H₁₂O₆. How many elements are present in this substance?
A. 3
B. 6
C. 12
D. 24
A
Study the chemical equation shown below:
2H₂O → 2H₂ + O₂
electricity
Which of the following statements about the equation is NOT correct?
A. Water is the reactant in this chemical reaction.
B. Hydrogen and oxygen are the products.
C. This shows a composition reaction.
D. Electricity is applied in the reaction.
C
To eliminate pathogenic organisms, milk is heated at 60°C, and then cooled rapidly. This process has saved a lot of lives, and is known as
A. fermentation.
B. preservation.
C. inoculation.
D. pasteurization.
D
Fruits and vegetables last longer when placed in the refrigerator. What explains this fact?
A. Low temperature slows down chemical reactions.
B. Low temperature speeds up chemical reactions.
C. Refrigerators are used to preserve food.
D. Refrigerators inhibit the production of enzymes.
A
If all types of microorganisms were removed from a body of freshwater, which of the following would most likely occur?
A. Fishes and plants would grow abundantly.
B. Water becomes safe for drinking and bathing.
C. Water-borne diseases would be minimized.
D. Organic wastes in the water would not be decomposed.
D
Which of the following organs/structures is not considered an endocrine gland?
A. Thyroid
B. Gall bladder
C. Testis
D. Islets of Langerhans
B
In the female human, testosterone is secreted by the
A. Ovaries.
B. Adrenals.
C. Uterus.
D. Pancreas.
A/B
The human body normally responds to the high concentration of sugar in the blood by secreting
A. Insulin.
B. Glucagon.
C. Estrogen.
D. Bile.
A