Matter

Matter

Matter is anything, such as a solid, liquid or gas that has weight (mass) and occupies space. For anything to occupy space, it must have volume. Thinking about it, everything on earth has weight and takes up space, and that means everything on earth is matter.

Mass is a property of a physical body. It is the measure of an object's resistance to acceleration (a change in its state of motion) when a force is applied.[1] It also determines the strength of its mutual gravitational attraction to other bodies.

Volume is the quantity of three-dimensional space occupied by a liquid, solid, or gas.

Density can be the amount of matter in a given volume, also known as mass density.

What are solids?

Solids are simply hard substances, and they are hard because of how their molecules are packed together. Examples include rock, chalk, sugar, a piece of wood, plastic, steel or nail. They are all solids at room temperature. They can come in all sizes, shapes and forms.

What is a liquid?

The particles in liquids are not as closely bonded, arranged and fixed in place as in solids. The particles in liquid can flow freely and can mix with particles from other liquids. Liquids have their atoms close together, so they are not very easy to compress.

What are gases?

Gas is everywhere, and it surrounds us. The air around us is a kind of gas. The atmosphere surrounding the earth is a gas too. Helium, Oxygen, Carbon dioxide and water vapour are all gases.

The particles in gases are very different from that of solids and liquids.

In gases, the particles are far apart from each other and arranged in a random way. The particles also move quickly in all directions. Gases can fill up any container of any shape and size. Gases can be compressed or squashed because the molecules are far from each other. When gas is compressed, the gas molecules move from an area of high pressure to low pressure.

What is a Physical Change?

In a physical change, the internal make-up of the object (molecules) stays the same, even after the change — only its form changes. The resulting element can be reversed into the object before. Changes that can be reversed are called a Reversible Change.

In a physical change, the state, shape or size of the object is changed. Pressure, temperature or motion can bring about a physical change.
Change in state:
Put some water into a plastic cup and place it in the freezer. After sometime the water changes into ice, right?

The water moved from a liquid state to a solid state. With a bit of heat energy, the ice will melt back into water. Note that the stuff that water is made up of, hydrogen oxygen, did not change, but its’ state changed from liquid to ice and back to liquid.

What is a Physical Change?

Physical properties are properties of an element or compound that can be observed without a chemical reaction of the substance. Density and electrical conductivity are examples of physical properties.

In a physical change, the substances are not altered chemically. No new products are formed. Chemical bonds are not broken in a physical change

A physical change can affect the size, shape or color of a substance but does not affect its composition. The substances may be changed to another phase (i.e. gas, liquid, solid) or separated or combined.

Examples:

when ice melts

when sulfur is mixed with iron filings.

breaking a glass

dissolving sugar in water

Growth

Growth

Human growth is far from being a simple and uniform process of becoming taller or larger. As a child gets bigger, there are changes in shape and in tissue composition and distribution. In the newborn infant the head represents about a quarter of the total length; in the adult it represents about one-seventh. In the newborn infant the muscles constitute a much smaller percentage of the total body mass than in the young adult. In most tissues, growth consists both of the formation of new cells and the packing in of more protein or other material into cells already present; early in development cell division predominates and later cell filling.

Childhood

Infants and children grow and develop at a rapid pace during the first few years of life. The development of both gross and fine motor skills helps a child go from a completely dependent newborn to an independently functioning toddler in about a 3-year span.

Characteristics	Implications
Physical growth is lower than during Infancy and early childhood.	Plan activities using large motor skills and introduce fine motor skills, one at a time
Muscular coordination and control are uneven and incomplete. Large muscles are easier to control than small muscles	Plan lots of physical activity with each meeting.
Able to handle tools and materials more skillfully than during preschool years.	Introduce new physical activities that require coordination such as roller skating, bike riding, rope jumping and simple outdoor games.
Can throw different-sized balls better than they can catch them. Most cannot bat well.	Provide projects that don’t require perfection and that can be successfully completed by beginners
Most can learn to snap fingers, whistle and wink.	Provide patient guidance and encouragement for fine motor activities.
May repeat an activity over and over to master it.

Adolescence

The period between childhood and young adulthood is a period of rapid change – physical, emotional, cognitive and social. During this time, children’s bodies change in different ways at different times. No two teenage bodies are the same.

Physical changes during adolescence

For girls, you might start to see early physical changes from about 10 or 11 years, but they might start as young as 8 years or as old as 13 years. Physical changes around puberty include:

·         breast development

·         changes in body shape and height

·         growth of pubic and body hair

·         the start of periods (menstruation).

For boys, physical changes usually start around 11 or 12 years, but they might start as young as 9 years or as old as 14 years. Physical changes include:

·         growth of the penis and testes (testicles)

·         changes in body shape and height

·         erections with ejaculation

·         growth of body and facial hair

·         changes to voice.

Maturity

As we age, our bodies change in physical ways. One can expect a variety of changes to take place through the early- and middle-adult years. Each person experiences age-related changes based on many factors: biological factors such as molecular and cellular changes are called primary aging while aging that occurs due to controllable factors, such as lack of physical exercise and poor diet, is called secondary aging.

Human Reproduction

Human Reproduction

Human reproduction is any form of sexual reproduction resulting in human fertilization, typically involving sexual intercourse between a man and a woman. During sexual intercourse, the interaction between the male and female reproductive systems results in fertilization of the woman's ovum by the man's sperm. These are specialized reproductive cells called gametes, created in a process called meiosis. While normal cells contains 46 chromosomes, 23 pairs, gamete cells only contain 23 chromosomes, and it is when these two cells merge into one zygote cell that genetic recombination occurs and the new zygote contains 23 chromosomes from each parent, giving them 23 pairs. After a gestation period, typically for nine months, is followed by childbirth. The fertilization of the ovum may be achieved by artificial insemination methods, which do not involve sexual intercourse.

Fertilization

Simply put, the definition of human fertilization is the union or joining of the egg and the sperm, resulting in a fertilized egg, otherwise known as a zygote. But the process of human fertilization is very complicated and comprised of many steps and components necessary to achieve the ultimate result of human life. Read on to learn how such small things work together to make a fertilized egg.

Process

The process of human fertilization is a complicated one, but the egg and sperm will unite in the long run. Although technical in nature, you could also look at it as a journey to find the perfect match. The egg will sit waiting for one sperm out of up to 150 million that begin the race, and it will merge with that sperm to create human life. While the egg waits, the sperm race and compete to be the first to penetrate the egg. When the one sperm and egg finally meet, electricity fills the air. Seriously, electric signals are released. Although the details may not be so romantic, remember that it is the journey that counts. Human fertilization begins with a woman's menstrual cycle. This cycle prepares a woman's body for fertilization. About half way through this cycle, the woman's body is ready to begin the process of human fertilization. It is at this point that an egg cell is released, or ovulated, into the Fallopian tube. Inside this Fallopian tube, fertilization will take place.

Pregnancy

The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long.

Living Things

LIVING THINGS

When you look at the world around you, how do you categorize or group what you see? In science, the broadest groupings are living and non-living. This may sound simple, but it is sometimes difficult to decide whether something is truly alive or not.

All living things share life processes such as growth and reproduction. Most scientists use seven life processes or characteristics to determine whether something is living or non-living.

Plants and Algae

 Did you know that seaweed is not a plant? First of all, algae may be unicellular, colonial, or multi-cellular. Plants, on the other hand, are only multi-cellular. Holdfasts, stapes and blades compose multi-cellular algae. In comparison, plants have roots, stems, leaves, flowers, fruits, seeds and cones. The roots of plants not only hold them in place, they nourish them. Plants possess vascular systems, which allow for the uptake and transport of water and nutrients. In contrast, each cell in algae must obtain its own nutrients from water for survival.

Animals and Fungi

Fungi and animals are very different from each other and classified as completely separate kingdoms. At the cellular level, both animals and fungi are composed of eukaryotic cells. Fungal cells differ from plant cells in that they do not have chloroplasts and cannot carry out photosynthesis to make their own food. They are similar to animal cells in that fungal cells have centrioles, the structures that organize the spindle during mitosis.

Human Body