Answer:
La historia de la química abarca un periodo de tiempo muy amplio, que va desde la prehistoria hasta el presente, y está ligada al desarrollo cultural de la humanidad y su conocimiento de la naturaleza. Las civilizaciones antiguas ya usaban tecnologías que demostraban su conocimiento de las transformaciones de la materia, y algunas servirían de base a los primeros estudios de la química. Entre ellas se cuentan la extracción de los metales de sus menas, la elaboración de aleaciones como el bronce, la fabricación de cerámica, esmaltes y vidrio, las fermentaciones de la cerveza y del vino, la extracción de sustancias de las plantas para usarlas como medicinas o perfumes y la transformación de las grasas en jabón.
Answer: The statement is false
Explanation:
A community refers to a group of plants and animals that occupy a given area and can adapt to the conditions of their environment. Hence, community include biotic factors (living organisms) and abiotic factors (non-living factors like soil, weather etc).
Thus, the statement is false
The correct answer is option A, that is, placer deposits.
The concentration of heavy deposits known as the placer deposits are produced by the gravitational action, generally found in streams. The minerals that take place as placer deposits comprise copper, gold, magnetite, cassiterite, and copper.
The formation of placer deposits takes place when the metal-bearing rock on land is weathered and the generated debris is washed down to the sea by the rivers. Further by the action of waves, currents, and rides the particles of heavy metal gets amassed to produce mineral sand deposits. These generally occur as beach deposits.
Muscles are required in breathing, talking, running, walking, and any body movement. Actin and myosins are protein filaments present in muscle cells that help to contract and relax or change the shape of muscles. Muscles are responsible for the movement or motion of organisms. Joints are the connection between two or more bones. Most joints are mobile.
Muscle strength is determined by several factors. Some of those are the physical shape, size, and innervation of the muscles.
Weak contraction
- Potassium accumulates in the sarcoplasm.
- Contracted lower sarcoplasm pH.
- Begin contraction with muscle already 50%.
- The circular arrangement of muscle fascicles.
Stronger contraction
- Increase in muscle belly circumference.
- A lesser proportion of motor neurons to muscle fibers.
- Increased recruitment.
- Increased stimulus frequency.
Answer: No
Explanation:
the freezing point of salt water is lower than that of pure water, due to the presence of the salt dissolved in the water
