Chemistry and Plant Systems Flashcards
Assessment
What is the vacuole?
The vacuole in plant cells is large and occupies most of the cell. It is filled with sap and stores water, wastes and nutrients. When it is full the vacuole pushes against the cell wall and helps to keep the plant rigid.
How are alkali metals different from each other?
Moving down group 1, alkali metals become:
Larger, softer and denser
Less heat-resistant, with lower melting and boiling points
And, more reactive.
What are molecules and compounds?
A molecule is a group of two or more atoms bonded together.
If a molecule consists of:
Only one element, it’s called a molecular element
Or, two or more different elements, it’s called a compound.
H2 and O2 are molecular elements, whilst H2O and CO2 are compounds.
All compounds are molecules, but not all molecules are compounds!
The elements in a compound are always combined in certain fixed proportions. For example, there are always two hydrogen atoms for every one oxygen atom in a water molecule. All of the molecules in a compound are identical.
What are the uses of oxygen?
It’s used in hospitals for people who struggle to breathe, particularly those with lung disease.
It’s also used by divers and hikers at high altitudes.
What are halogens?
The halogens are nonmetals found in group 17 of the periodic table.
There are six halogens:
Fluorine (F)
Chlorine (Cl)
Bromine (Br)
Iodine (I)
Astatine (At)
And, tennessine (Ts).
All halogens are one electron short of a full outer electron shell.
How are non-metals different across the periodic table?
Nonmetallic character increases:
Up a group,
And across a period from left to right.
So, the closer an element is to the top-right corner of the periodic table, the more nonmetallic it is.
How are noble gases different from each other?
Moving down group 18, the noble gases become:
Larger
And, more heat-resistant, with higher melting and boiling points.
What are the rows of the periodic table called?
Periods.
What is the difference between a molecule and a compound?
A molecule is made of two or more atoms bonded together, while a compound consists of molecules that contain two or more different elements.
How do we represent elements?
Elements are represented by chemical symbols, which are one or two letters long.
Some of these symbols come from the Latin names for elements.
These chemical symbols are universal—allowing scientists to communicate, even if they speak different languages!
What are the properties of metals?
Solid at room temperature (except mercury)
Usually silver in colour
Lustrous
Malleable
Ductile
Good conductors of heat and electricity
Very reactive
High melting and boiling points
Identify which subatomic particle is not found in the nucleus.
Electron
What are the uses of chlorine?
It’s used in household cleaning products and bleach.
Pools are often chlorinated to make them safe to swim in!
Describe the male parts on a flower.
Flowers have two male parts:
A thin stalk called the filament, attached to the flower.
A small sack called the anther, attached to the top of the filament. The anther contains a fine yellow powder called pollen, which produces sperm cells.
Together, these two male parts are called the stamen.
Determine which of the following features all compounds share.
Have fixed chemical formulas, Have specific sets of properties, Contain two or more different elements
How are electrons arranged?
An atom’s electron configuration is the particular way its electrons are organised!
Electrons fill up the innermost electron shell first, which has space for two electrons.
Once the first shell is full, electrons fill up the second shell, which has space for eight electrons.
When the second shell is completely full, electrons fill the third shell, which has space for 18 electrons.
As atoms get bigger in size, they have more electron shells and there are more rules to consider—but we don’t have to worry about this for now!
Where are electrons located in an atom?
Electrons orbit around the nucleus in energy levels or shells.
What are organ systems?
Give example in plants
Organ systems are the result of several organs coming together to do even more complex jobs.
The plant organ systems include the:
Shoot system—which is made up of leaves, stems, flowers and fruit
And, the root system—which is made up of all the roots.
What is the equation for photosynthesis?
Water + Carbon dioxide -> Glucose + Oxygen
What are the columns of the periodic table called?
Groups
Describe the plant structure
Flowers are for sexual reproduction. Fruits contain the seeds. Stems are for structure and support. Roots are for anchorage and absorption of water. Leaves photosynthesize and therefore create food for the plant.
What are the palisade cells?
This layer is tightly packed and contains large numbers of chloroplasts; a large amount of photosynthesis occurs here
What are stems?
Stems are the organ of a plant that keeps it upright and transports nutrients around the plant.
The stems grow up and spread out above ground.
Stems can come in lots of shapes and sizes.
From the thorny stems on roses to thick tree trunks and winding vines.
What do leaves do?
Leaves allow plants to breathe—or exchange gases.
They take in carbon dioxide from the air and then release oxygen back into it.
Plant leaves are also used to produce food for plants.
They harness the energy from sunlight to turn carbon dioxide and water into glucose and oxygen.
What are the uses of nitrogen?
To preserve packaged foods—when combined with carbon dioxide it helps prevent food from spoiling
And, in the pharmaceutical industry.
What is an atom?
All matter is made up of tiny building blocks called atoms.
Atoms are the smallest unit of matter to exist.
They have a radius of about 0.1 nanometres.
Atoms are too small to be seen with the human eye.
Even a powerful microscope can’t visualise them!
What are plants made of?
All living things are made out of cells.
Not all cells are the same though.
Cells are specialised to do special things to make them exceptionally good at their specific job.
This is why a mango tree has different cells in its fruit—that let it store delicious sugar
Compared to those in its tree trunk—that help keep the tree upright.
Describe pollination by insect.
Structure usuall small, some with many flowers in one head, brightly coloured petals especially blues and yellows, small amounts of nectar, strong scent, often strongly marked with landing guides. Often short stamens and smallanthers, close to nectar source in most flowers, sticky pollen. Short style, small stigma close to nectar source. (Insects have poor eyesight, low intelligence, good sense of smell, small bodies.)
What are the lower epidermal cells?
Transparent layer of cells on the bottom of the leaf that act like a skin
Describe pollination by wind.
Structure is often small but with many flowers in one head, ofte no petals, not brightly coloured, no nectar, no scent. Long stamens with large anthers exposed. Long style with exposed stigma; stigma has large surface area - often look like brushes
What holds an atom together?
Opposite charges attract each other.
In an atom, the negative electrons are attracted to the positive nucleus.
This attraction acts like glue to keep the atom together.
The overall charge of an atom is determined by the number of protons and electrons.
When the number of electrons equals the number of protons, each negative charge is balanced by a positive charge.
This means the overall atom has no charge—which we call neutral.
What is air space?
Spaces in the leaf where gases move around cells
What are roots for?
Roots help to anchor plants into the ground.
This is due to the web-like way that they spread out in the soil.
Roots also help to absorb nutrients from the soil.
Minerals like nitrogen, phosphorus and potassium are absorbed from the soil
And, so is water when it rains.
What is the process called when a liquid turns into a gas?
Evaporation or boiling.
What makes elements different?
Every element has a different atomic number, which is the unique number of protons in the atoms which make up the element.
Meanwhile, an element’s mass number is the number of protons and neutrons in the atom’s nucleus.
Along with the chemical symbol, every element’s atomic number and mass number can be read off the periodic table.
What are isotopes?
All atoms of the same element have the same number of protons.
However, they can have different numbers of neutrons.
Isotopes are atoms of the same element with different numbers of neutrons.
So, isotopes of an element have different atomic masses!
What is a chemical formula?
A representation of a molecule showing the elements involved and the number of atoms of each element (e.g., H₂O for water).
What are leaves?
Leaves are the organ of a plant that uses photosynthesis to produce the plant’s food.
Despite leaves coming in many shapes and sizes, all leaves share a few key features.
Petioles—the short stems that connect the leaves to the plant.
Lamina—the flat green part that catches the sunlight.
Veins—the thin ribs in the leaf that carry nutrients around the leaf and give it structure.
What are alkali metals?
Alkali metals are found in group 1 of the periodic table.
There are six alkali metals:
Lithium (Li)
Sodium (Na)
Potassium (K)
Rubidium (Rb)
Caesium (Cs)
And, francium (Fr).
All group 1 elements have one outer shell electron.
Label the key information on a tile of the periodic table.
- Atomic number
- Chemical symbol
- Name
- Atomic mass
What are stems made of?
Plant stems are made up of two types of tubes, which together are called the vascular bundle.
Xylem are straw-like tubes that carry water from the roots to the leaves.
These only travel in one direction, from the roots up to the leaves.
Phloem are tubes that carry the sugar produced in the leaves all around the plant.
These travel in both directions, carrying nutrients down the plant and back up again.
What structure do noble gases have?
Single atoms
What are the properties of non-metals?
Gases or solids at room temperature (except bromine)
Often dull
Brittle
Poor conductors of heat and electricity
Low melting and boiling points
What are the uses of aluminium?
Since it doesn’t react with air or water, it’s used in cans and kitchen utensils.
It can be used as a wrap to cover food because it’s malleable!
What is a chemical bond?
An attractive force that binds atoms together
How are halogens different from each other?
Moving down group 17, halogens become:
Darker in colour
More heat-resistant, with higher melting and boiling points
And, more reactive.
What is an ion?
An atom or molecule with a net electrical charge due to the loss or gain of electrons.
What is sublimation?
The process of a solid turning directly into a gas.
What are mesophyll cells?
Loosely packed cells that give this part of the leaf a spongy appearance
What is pollination?
Fertilisation takes place when a male gamete and female gamete join to form a zygote.
While the zygote forms, the ovule forms a seed.
The ovary surrounding the ovule also starts to change into a fruit, which protects and nurtures the zygote.
For these zygotes to become new plants, germination needs to happen.
This requires water, oxygen and the right temperature!
What does the cell wall do?
The cell wall keeps the shape of plants and keep it upright.
What are the properties of noble gases?
Monatomic gases at room temperature
Chemically inert
Colourless
Odourless
