June 8, 2018

Fizyka: Ciepło właściwe

Source: Fizykon.org

Przyrost temperatury wody jest wprost proporcjonalny do ilości pobranego przez nią ciepła.

T ~ Q

Ilość pobranego przez wodę ciepłą potrzebnego do uzyskania danego przyrostu temperatury jest wprost proporcjonalna do masy wody.


Ew = Q
Q ~ m

Ilość pobranego przez ciało ciepła potrzebna do zwiększenia temperatury o tę samą wartość zależy od rodzaju substancji, z której zbudowane jest ciało.

Ciepło właściwe określa, ile energii trzeba dostarczyć, aby zwiększyć temperaturę 1kg danej substancji o 1K (o 1C). Ciepło właściwe oblicza się jako iloraz ciepła dostarczonego ciału i iloczynu jego masy i przyrostu temperatury.

c = Q / m×T

Ilość ciepła, jaką podbiera ciało podczas ogrzewania, można obliczyć ze wzoru Q = c×m×△T.

Ilość ciepła Q pobranego przez ciało jest wprost proporcjonalna do masy ciała m i przyrostu temperatury △T:

Q = c×m×T

gdzie c jest współczynnikiem proporcjonalności, zwanym ciepłem właściwym, charakterystycznym dla danego ciała.


Ciepło właściwe - jest to cecha substancji określająca, ile ciepła dana substancja musi pobrać, aby 1kg jej masy został ogrzany o 1K (1℃). Ciepło właściwe oblicza się jako iloraz ciepła dostarczonego ciału i iloczynu jego masy i przyrostu temperatury.

June 7, 2018

Biology: Different kinds of Mammals

Source: Mammal's Locomotion


Monotremes 
Source: World Atlas
Monotremes are mammals that lay eggs.


Marsupials
Source: San Diego Zoo
Marsupials are mammals whose young are born alive, but at an early stage of development, and they usually continue to develop in a pouch on their mother's body.


Placental Mammals 
Source: World Wild Life
A placental mammal develops inside its mother's body until its body systems can function independently.

June 6, 2018

Chemia: Kwas Węglowy

Source: Chemia - Gimnazjum
CO + H₂O ⟶ H₂O₃

Właściwości fizyczne
  • ciecz
  • bezbarwny
Właściwości chemiczne
  • nieorganiczny kwas tlenowy
  • bezwonny
  • nietrwały - łatwo ulega rozkładowi

Zastosowania kwasu węglowego

Przemysł spożywczy
Woda gazowana jest to wodny roztwór kwasu węglowego.

Synteza węglanów
Związki chemiczne zawierające resztę kwasową kwasu węglowego to węglany.

Medycyna
W uzdrowiskach kwas węglowy jest wykorzystywany do tzw. kąpieli kwasowęglowych leczących choroby skórne.

Laboratoria chemiczne
CO + H₂O stosuje się w reakcjach chemicznych.

June 5, 2018

Chemia: Kwas Azotowy (V)

Source: Chemia - Gimnazjum

NO₅ + H₂O ⟶ 2 HNO₃

Reakcja ksantoproteinowa - reakcja charakterystyczna białek ze stężonym roztworem kwasu azotowego (V).

Właściwości fizyczne
  • ciecz
  • bezbarwny
  • ma gęstość około 1.5 raza większą od gęstości wody
Właściwości chemiczne
  • nieorganiczny kwas tlenowy
  • ma charakterystyczny ostry zapach
  • żrący
  • powoduje żółknięcie białek w reakcji ksantoproteinowej
  • na silne właściwości utleniające
Zastosowania kwasu azotowego (V)

Przemysł farmaceutyczny
W chorobach układu krążenia i serca jest stosowana nitrogliceryna - lek produkowany z wykorzystaniem HNO₃.

Paliwa rakietowe
Kwas azotowy (V) jest składnikiem paliw rakietowych.

Produkcja perfum
Substancje zapachowe będące składnikami wielu perfum to wytworzone w laboratoriach chemicznych syntetyczne ambra i piżmo. Do ich produkcji wykorzystuje się HNO₃.

Rolnictwo
Kwas azotowy (V) stosuje się do produkcji nawozów sztucznych.

Produkcja lakierów i farb do drewna

June 4, 2018

Biology: Mammals

Source: National Geographic
All mammals are endothermic vertebrates with a four-chambered heart, and skin covered with fur or hair. The young of most mammals are born alive, and every young mammal is fed with milk produced in its mother's body. In addition, mammals have teeth of different shapes that are adapted to their diets.

Fur and Hair
Source: Animals Australia 
All mammals have fur or hair at some point in their lives.
Fur and hair help mammals maintain a stable body temperature in cold weather.

Mammals are endotherms, which means that their bodies produce enough heat to maintain a stable body temperature regardless of the temperature of their environment.


Teeth
Source: National Geographic
Endotherms need a lot of energy to maintain their body temperature, and that energy comes from food. Mammals' teeth are adapted to chew their food, breaking it into small bits that make digestion easier.

Most mammals have teeth with four different shapes. Incisors are flat-edged teeth used to bite off and cut parts of food. Canines are sharply pointed teeth that stab food and tear into it. Premolars and molars grind and shred food into tiny bits.


Getting Oxygen to Cells

All mammals breathe with lungs.

Mammals breathe in and out because of the combined action of rib muscles and large muscle called the diaphragm located at the bottom of the chest.

Mammals have a four-chambered heart and a two loop circulation. One loop pumps oxygen-poor blood from the heart to the lungs and then back to the heart. The second loop pumps oxygen-rich blood from the heart to the tissues of the mammal's body, and then back to the heart.


Nervous System and Senses

The nervous system and senses of an animal receive information about its environment and coordinate the animal's movements. The brains of mammals enable them to learn, remember, and behave in complex ways.

The senses of mammals are highly developed and adapted for the ways that individual species live.

Most mammals have good hearing.

Most mammals have highly developed senses of smell.


Movement
Source: Animal Ark
One function of a mammal's nervous system is to direct and coordinate complex movement.


Reproducing and Caring for Young

Mammals have internal fertilization. Although a few kinds of mammals lay shelled eggs, the young of most mammals develop within their mothers' bodies and are never enclosed in an eggshell. All mammals, even those that lay eggs, feed their young with  milk produced in mammary glands.

Young mammals are usually quite helpless for a long time after being born.

Stay with their mother or both parents for an extended time.

May 25, 2018

Biology: Birds

What Is a Bird?
Source: Wikipedia
A bird is an endothermic vertebrate that has feathers and a four-chambered heart, and lays eggs. Birds have scales on their feet and legs, most birds can fly.

The bodies of birds are adapted for flight.
The bones of a bird's forelimbs form wings. Many of a bird's bones are nearly hollow.
Flying birds have large chest muscles that move the wings.
Feathers are a major adaptation that help birds fly.

Feathers

Source: Bird Academy
Feathers are a major adaptation that help birds fly.

A contour feather is one of the large feathers that give shape to a bird's body. The long contour feathers that extend beyond the body on the wings and tail are called flight feathers. When a bird flies, these feathers help it balance and steer.

Down feathers are specialized to trap heat and keep the bird warm. Down feathers are found right next to a bird's skin.
Down feathers are soft and flexible.

Food
Source: dixonapbio-taxonomywiki-2016
Birds have no teeth. To capture, grip, and handle food, birds primarily use their bills.

Many birds have an internal storage tank, or crop, that allows them to store food inside the body after swallowing it.

Delivering Oxygen to Cells

Birds have a system of air sacs in their body that connects to the lungs. The air sacs enable birds to extract much more oxygen from each breath of air than other animals can.

Birds have hearts with four chambers - two atria and two ventricles.

Nervous System and Senses

In order to fly, birds must have very quick reactions

A bird can react quickly because of its well-developed brain and finely tuned senses of sight and hearing.

Diversity of Birds

In addition to adaptations for flight, birds have adaptations - such as the shapes of their legs, claws, and bills - for living in widely diverse environments.

May 24, 2018

Biology: Reptiles

Protection from Drying Out

A reptile is an ectothermic vertebrate that has lungs and scaly skin.

Reptile can spend their entire lives on dry land.

About 7000 kinds of reptiles are alive today, but they are only a tiny fraction of a group that once dominated the land.

The eggs, skin, and kidneys of reptiles are adapted to conserve water.



An Egg With a Shell

A reptile's egg has a shell and membranes that protect the developing embryo and help keep it from drying out. Reptiles lay their eggs on dry land. Reptile eggs are soft and leathery.


Skin and Kidneys

Reptile have dry, tough skins covered with scales. This scaly skin protects reptiles and helps keep water in their bodies.

The kidneys of reptiles concentrate the urine so that they lose very little water.


Obtaining Oxygen from the Air

Most reptiles breathe entirely with lungs.

The hearts of most reptiles have three chambers - two atria one ventricle.


Lizards

Source: San Diego ZOO
Most reptiles alive today are either lizards or snakes.

Both have skin covered with overlapping scales.

They shed their skins and live in warm areas.

Lizards have four legs, usually with claws on the toes.

They have long tails, slender bodies, movable eyelids and external ears.

A few lizards, are herbivores that eat leaves. Most lizards are carnivores that capture food by jumping at it.

Snakes

Source: San Diego ZOO
Snakes are able to live in almost every sort of habitat, from deserts to swamps.

Snakes have no legs, eyelids, or external ears, and most snakes have only one lung.

Snakes move by contracting, or shortening, bands of muscles that are connected to their ribs and back bones.

All snakes are carnivores.

The bones of a snake's skull can move to let the snake swallow an animal much larger in diameter than itself.

Turtles

Source: San Diego ZOO
A turtle is a reptile whose body is covered by a protective shell, which is made from the turtle's ribs and backbone.

The bony plates of the shell are covered by large scales made from the same material as the skin's scales.

The largest turtles are carnivores.


Alligators and Crocodiles

Source: San Diego ZOO
Alligators have broad, rounded snouts, with only a few teeth visible.

Crocodiles have pointed snouts, and you can see most of their teeth. Both alligators and crocodiles spend much of their days resting in the sun or lying in the water.

Alligators have broad, rounded snouts, with only a few teeth visible.

Crocodiles have pointed snouts, and you can see most of their teeth. Both alligators and crocodiles spend much of their days resting in the sun or lying in the water.

Alligators and crocodiles are carnivores that hunt mostly at night.

Unlike most other reptiles, crocodiles and alligators care for their eggs and newly hatched young. For as long as a year, mother stays near her young.