حل أوراق عمل Writing Part في العلوم باللغة الإنجليزية للصف السابع (2)

Hessa Bint Mohammed School

End of Term 2-Writing Part

Particles are very close. Particles vibrate in place. Particles can move past each other. So, liquids can flow Particles are far apart. Move at high speed.

2. Circle the words that best describe what happens as heat is added to the solid.

3. Potential energy is stored energy due to the interactions between particles or objects. Gases have more potential energy than liquids or solid. 4. Which have more potential energy bubbles in carbonated water or liquid water particles?

6. An atom is a small particle that is the building block of matter.

7. Nitrous oxide and dinitrogen trioxide contain the same elements nitrogen and oxygen, but nitrous oxide is a colorless gas while dinitrogen trioxide is a blue liquid. Why?

They contain the same elements, but different ratios. So they are different compounds. 8. A chemical formula is a group of chemical symbols and numbers that represent the elements and the number of atoms of each element that makes up a compound.

10. The relationship between volume and temperature is called Charles Law.

11. Charles’s law states that the volume of a gas increases with increasing temperature if the pressure is constant.

12. Thermal energy always transfers from a region of high temperature(hot) to a low temperature(cold).

Hot، cold

13. How the thermal energy transferred?

Thermal energy is transferred to the cup, hands and the air.

14. What happens to the motion of the particles and kinetic energy of the particles inside an inside basketball after it has been left out in the cold?

As temperature decreases particles lose kinetic energy and volume decreases.

15. Label open system, closed system

Open system heat and matter transfer

Closed System heat transfer but no matter transfer

16. Density is the mass per unit volume of a substance. Density=mass/volume Every substance has its density. So we can identify unknown substances using density.

Slope=density= rise run