Science yearly

What are the three types of forces that can act on an object?

Push, pull, or twist.

What is the definition of balanced forces?

Forces that cancel each other out and are equal in magnitude but act in opposite directions.

What is the definition of unbalanced forces?

Forces that are not equal in magnitude, causing a change in motion.

What unit is used for measuring force?

Newton

What does Newton's First Law state?

An object at rest stays at rest and an object in motion stays in motion unless acted upon by an external force.
The law of interia

Give an example of Newton's First Law of Motion.

A book on a table remains stationary until a force moves it.

What does Newton's Second Law (Law of Acceleration) state?

Acceleration is directly proportional to net force and inversely proportional to mass (F=ma).

How is Newton's Second Law exemplified with different mass objects?

A lighter object will accelerate more than a heavier one when the same force is applied.

What does Newton's Third Law (Action-Reaction Law) state?

For every action, there is an equal and opposite reaction.

Provide an example illustrating Newton's Third Law.

When a rocket expels gas downward, it creates an upward force that propels the rocket.

How do you convert km/h to m/s?

Divide the speed in km/h by 3.6.

How do you convert m/s to km/h?

Multiply the speed in m/s by 3.6.

What is the speed of a car that travels 300 meters in 10 seconds in km/h?

108 km/h.

How far does a killer whale swim if it swims at 13 m/s for half a minute?

390 meters.

What is the definition of distance?

A measure of how far an object travels.

What is displacement?

The straight-line distance from an object's starting position to its current position, with direction included.

What are scalar and vector quantities?

Distance is a scalar quantity; displacement is a vector quantity.

What is the formula to calculate speed?

Speed = Distance / Time.

What is the definition of velocity?

Speed of something in a given direction

What is the relationship between distance and displacement in a round trip?

Distance is the total path traveled; displacement is zero if starting and ending points are the same.

What is natural selection?

A process through which populations adapt and change due to variability in traits that enhance survival.

What is artificial selection?

The intentional breeding of plants or animals for specific traits by humans.

Who is associated with the theory of evolution by natural selection?

Charles Darwin.

What is the significance of fossil records in Darwin's theory?

They provide evidence of extinct species and common ancestry over time.

What are homologous structures?

Anatomical features in different species that have similar origins but may serve different functions, indicating common ancestry.

What is a mutation?

A change in the DNA sequence that can introduce new alleles into a population.

What is gene flow?

The movement of alleles in and out of a population through migration.

What is genetic drift?

Random changes in allele frequencies in a population due to chance events.

What is meiosis?

A type of cell division that produces four genetically distinct haploid cells for sexual reproduction.

What are dominant and recessive alleles?

Dominant alleles are expressed in the phenotype; recessive alleles are expressed only when two copies are present.

What is DNA replication?

The process through which a cell duplicates its DNA before cell division.

What enzyme unwinds the DNA during replication?

Helicase.

What is the role of DNA polymerase?

It adds nucleotides to the growing DNA strand during replication.

What causes nondisjunction?

Failure of chromosomes to separate properly during meiosis, leading to gametes with an abnormal number of chromosomes.

What is predation in ecology?

A relationship where one organism consumes another.

What is symbiosis?

Long-term interactions between different species, which can be mutualistic, commensalistic, or parasitic.

What are genetically modified organisms (GMOs)?

Organisms whose DNA has been altered through genetic engineering to enhance desired traits.

What is the function of the ovaries in the female reproductive system?

To produce eggs and reproductive hormones.

What is the function of the testes in the male reproductive system?

To produce sperm and testosterone.

What is the purpose of cell division?

To create new cells for growth, repair, and reproduction.

What is binary fission?

A form of asexual reproduction where one cell divides into two identical cells.

What does a catalyst do in a chemical reaction?

It increases the reaction rate by lowering the activation energy needed for the reaction.

What is an ionic compound?

A compound formed by the transfer of electrons from metals to nonmetals, creating charged ions that attract each other.

What is the formula for hydrochloric acid?

HCl.

What gas is released when acids react with metals?

Hydrogen gas.

What is the general reaction between an acid and a carbonate?

Acid plus carbonate produces salt, water, and carbon dioxide.

What are polyatomic ions?

Ions composed of two or more atoms covalently bonded that carry a net charge.

What is the relationship between atomic number and protons?

The atomic number is equal to the number of protons in an atom.

Define electron configuration.

The distribution of electrons among the orbitals of an atom.

How are cations and anions formed?

Cations are positively charged ions formed by losing electrons; anions are negatively charged ions formed by gaining electrons.

What is the significance of valence shells in chemical bonding?

Valence shells determine the chemical reactivity of an atom by indicating how many electrons are available for bonding.

What is the rule for naming ionic compounds?

Name the metal first, then the nonmetal with the suffix -ide, unless it is a polyatomic ion.

Acid + base = ?

Salt + water

Acid + carbonate = ?

Salt + carbon dioxide + water

Acid + metal = ?

Salt + hydrogen gas

Examples of Acid metal reactions

Zinc + Hydrochloric acid —> Zinc Chloride + hydrogen gas
Sulfuric acid + magnesium —> Magnesium sulfate + hydrogen gas

Acid + carbonate examples

Hydrochloric acid + zinc carbonate —> Zinc chloride + Carbon dioxide + water

Nitric acid + iron carbonate —> iron nitrate + carbon dioxide + water

Acid and base reaction example

Hydrochloric acid + sodium hydroxide —> sodium chloride + water

What are acids?

Corrosive substances that release hydrogen ions react with solids that break down the solids. Not all acids are strong, weak acids can be found in lemons

what are bases?

Substances that accept hydrogen ions, they are usually bitter, slippery or soapy to touch, some bases are corrosive.

common acids

hydrochloric acid, sulfuric acid, nitric acid, acetic acid

What does electronic configuration determine?

Determines how an atom will react to another atom

what is absolute dating?

measures the actual date of a specimen determined by the radioactivity elements present in a specimen an example: radiocarbon dating

What is relative dating?

provides approximate dates of specimens from the rocks around the specimen

Formula for velocity

= Displacement / Time.