States of matter
Lists all the states of matter.
Solid, liquid, gasous, plasma, bose-einstein condensate (BEC).
Which are all the phase transitions?
Melting, freezing (solidification), evaporation (boiling), condensation, sublimation and deposition.
What are physical properties?
Physical properties are characteristics that can be measured and observed without interacting with the composition.
What is an atom?
An atom is the smallest unit into which matter can be divided without the release of electrically charged particles.
How many periods and groups are there in the periodic table?
There are 7 horyzontal periods and 18 vertical columns (groups).
Why a solid mantein a fixed shape?
A solid maintains a fixed shape because the particles that make up the solid are packed closely together.
How is called the phase that goes from solid to gas?
The process is called sublimation.
Why are mass and volume classified as extensive properties?
Because they depend on the amount of substance in a material.
Whichh are the three major subatomic particles?
Protons, neutrons and electrons.
What is the main difference between a molecule of an element and a molecule of a compound?
A molecule of an element consists of one or more atoms of the same kind while a molecule of a compound has different types of atoms.
Why does a liquid take the shape of its container while a solid does not?
A liquid takes the shape of its container because its particles are close together but can move and slide past one another, while in a solid the particles are tightly packed and can only vibrate.
What is steam?
Steam is the gaseous form of water.
What makes chemical properties different from physical properties?
Chemical properties describe mainly how a substance interacts with other substances.
Where the subatomic particles are located?
Protons and neutrons are inside the nucleous while electrons orbitate around around it in trajectories called orbitals.
Who was the chemist that first standardized the periodic table?
The russian Dimitri Mendeleev.
Why can gases be compressed easily while liquids and solids can't?
Because in a gas the particles are bonded by weak forces while in a liquid and in a solid the particles are bonded together by strong forces.
In science, a sistem is the portion of matter that is being investigated: true or false?
True
How can you tell if a phenomenon is physical rather than chemical?
In a physical phenomenon the substance has the same composition while in a chemical one it changes.
What is the difference between the atomic number and the mass number?
The atomic number is the number of protons while the mass number is the total number of protons and neutrons.
How is a covalent bond formed?
A covalent bond is formed when two atoms share a pair of electrons.
Which are the conditions to form Bose Einstein Condensate?
Extremely low temperatures (near absolute zero).
Which are the particles that have more energy in evaporation?
The particles on the surface.
Why a chemical phenomenon involves the appearance of new substances?
Because in a chemical phenomenon we have structural rearrangements of the particles when two substances enter in contact (react).
How can an atom become an ion and what determines this change?
An atom becomes an ion when it gains on loses electrons, acquiring a charge, either positive or negative.
Explain how the molecular structure of a molecule can influence the chemical and physical properties of a substance? Give at least two examples of properties influenced.
Molecular structure determines the three-dimensional arrangement of atoms and it determines several propertier, such as reactivity and polarity.