Một xe xuất phát lúc 9 giờ 30 phút , chuyển dộng thẳng đều từ A đến B với vận tốc 40 km/h

"In a pure substance all the particles must be identical; therefore pure substances are composed only of elements." Do you agree

kenny6666 [7]

I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.

'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.

These example substances are all compounds, not elements.

6 0

2 years ago

Which of the following phenomena are due to the electric interaction? (Select all that apply.) surface tension in water friction

Eddi Din [679]

Answer:

Surface tension in water

Friction between tires and pavement

Dissolution of salt in water

Explanation:

Surface tension in water: It is due to the electrostatic force of attraction (cohesive force) between water molecules.

Friction between tires and pavement: It is due to the attractive force between tires and pavement.

Dissolution of salt in water: The ions of $Na ^ +$ and $Cl ^ -$ separate due to the strong attraction of water molecules.