What is Earth's main source of light and warmth?

An electric lamp shines and becomes warm. What forms does its electrical energy change into?

Pupils wave a cloth with balls on top. In what order does energy pass between them?

How do green plants use sunlight to meet their need for nourishment?

What supplies a child's body with energy for running?

Lito opens the curtains and the room becomes brighter. What is the source of this light?

Why can we see the Moon at night?

At a road crossing, what do red, yellow, and green lamps communicate to drivers?

How can Ana protect her eyes when a very bright lamp shines toward her?

The classroom will be empty until tomorrow. What should the teacher do with its electric fan to save electricity?

What must a guitar string do to produce a note?

How does a nearby speaker's voice reach our ears?

A knock travels through a steel rod and through air. In which material does it travel faster?

Which statement about sound in water is correct?

Which box represents the air that carries sound from a classroom bell?

Which device uses sound to warn road users?

Which pair contains only sounds made by animals?

Which school tool uses sound to signal a change of activities?

What should Ben do if the music in his earphones seems painfully loud?

Liza compares sound traveling through a table and through air. Which should she keep unchanged?

What name is given to thermal energy moving between objects because their temperatures differ?

A pan is warmer than Riza's hand. If she touches it, in what direction will thermal energy move?

What happens when ice is warmed just above its melting temperature?

Why does wearing a jacket help someone feel warmer on a cool morning?

These boxes show water at different temperatures. Which box would spread a drop of coloring more quickly?

A metal spoon in warm soup becomes warm. What process carries thermal energy along the spoon?

As water warms in a pot, warmer water rises and cooler water sinks. What is this process called?

Rice is heated in water. Which change usually occurs as it cooks?

Which action should an adult take with the LPG supply after cooking?

An adult must leave the kitchen while frying food on an LPG stove. What should happen first?

What is the dark, well-decayed organic material found in many garden soils called?

Mang Tino rubs a dry sample between his fingers. It feels gritty and has large grains. What soil type is it?

What soil type has the smallest mineral particles and usually holds water strongly?

A dry sample feels smooth and floury, with grains smaller than sand but larger than clay. What soil type is it?

What balanced mixture of sand, silt, and clay is often suitable for garden vegetables?

What soil material can be shaped while wet and fired to make a durable flowerpot?

Pupils compare water retention using equal amounts of different soils. How should they prepare the water for a fair test?

To test how planting materials affect growth, what should differ among pots of otherwise matching seedlings?

Why do farmers build terraces on steep hillsides in the Cordillera?

Which disposal method best protects garden soil from used rechargeable batteries?