Grade 7 practice Question

Questions and Answers

What is the primary function of the endocrine system?

To produce and regulate chemical substances called hormones

What is the term used to describe the constant state of the internal environment?

Homeostasis

What do hormones regulate in the body?

Growth, development, mood, tissue function, metabolism, and sexual function

What is released in small amounts from glands and transported in the bloodstream to target organs or cells?

Hormones Signup and view all the answers

Which gland is considered the master gland in the endocrine system?

Pituitary gland Signup and view all the answers

What would happen if homeostasis fails?

The body could become ill or result in death Signup and view all the answers

What is the primary function of hormones in the body?

To stabilize the body's internal environment Signup and view all the answers

Which gland produces hormones that stimulate or suppress hormone secretions?

Hypothalamus Signup and view all the answers

What is the result of an excess of thyroxine in the body?

Hyperactivity Signup and view all the answers

What is the term for the body's automatic response to perceived threats?

Fight or flight response Signup and view all the answers

What is the role of the pituitary gland in hormone regulation?

To act as a link between the hypothalamus and other endocrine glands Signup and view all the answers

What would be the result of a break in the hormone regulation pathway?

A disorder or disease may occur Signup and view all the answers

What is the primary purpose of responding to stimuli in humans?

To protect themselves from danger or for survival Signup and view all the answers

What is the term used to describe a change in the environment?

Stimulus Signup and view all the answers

What do human senses include?

Sight, hearing, smell, taste, and touch Signup and view all the answers

What happens when a stimulus is detected by a sensor?

The signal is converted into a response Signup and view all the answers

Where can the signal from a sensor be processed?

In an area in between the sensor and the brain Signup and view all the answers

What is the charge of a neutron?

No charge Signup and view all the answers

What is the number of electrons in the first shell of an atom?

2 Signup and view all the answers

What is the relationship between the number of protons and electrons in an atom?

The number of protons is equal to the number of electrons Signup and view all the answers

What is the term for the arrangement of electrons in energy levels around the nucleus of an atom?

Shells Signup and view all the answers

What is the atomic number of an atom equal to?

The number of protons in the nucleus Signup and view all the answers

What is the atomic mass of an atom equal to?

The number of protons and neutrons in the nucleus Signup and view all the answers

What is the maximum number of electrons that can occupy the second shell?

8 Signup and view all the answers

Calcium has an atomic number of 20. What is the electronic configuration of the element Calcium (Ca)?

2,8,10 Signup and view all the answers

What do the circles represent in a Dot & Cross diagram?

Shells Signup and view all the answers

Chlorine has an atomic number of 17. What is the electronic configuration of the element Chlorine (Cl)?

2,8,7 Signup and view all the answers

What happens to the particles in a liquid as they are heated?

They move faster and escape from the surface of the liquid Signup and view all the answers

What is a molecule?

Two or more atoms joined chemically Signup and view all the answers

What is the term for the fundamental building block of all materials?

Atom Signup and view all the answers

What happens to the particles in a gas as it is cooled?

They move slower and come closer together Signup and view all the answers

What is the term for a pure substance that is made up of two or more different types of atoms chemically combined?

Compound Signup and view all the answers

What occurs when the particles in a gas are cooled?

They move slower and come together Signup and view all the answers

What is the fundamental building block of all materials?

Atom Signup and view all the answers

What is the term for a pure substance that is made up of two or more different types of atoms chemically combined?

Compound Signup and view all the answers

What is matter?

Any substance that has mass and volume Signup and view all the answers

What are the three main states of matter on Earth?

Solid, Liquid, Gas Signup and view all the answers

What is a characteristic of particles in a solid?

They hold their own shape Signup and view all the answers

What happens to the shape of a liquid when it is poured into a container?

It takes the shape of the container Signup and view all the answers

What determines the amount of space an object takes up?

The amount of matter in the object Signup and view all the answers

What is the reason for a substance to change from one physical state to another?

Gain or loss of heat energy Signup and view all the answers

What happens to the particles in a solid as the temperature increases?

They vibrate and expand Signup and view all the answers

What is the state of matter where particles have the highest energy?

Gas Signup and view all the answers

What happens to the particles in a liquid as they are cooled during freezing?

They move slower Signup and view all the answers

What is the process where particles in a liquid escape to form a gas?

Evaporation Signup and view all the answers

What is the state of matter where particles are held in a fixed position by the forces of attraction?

Solid Signup and view all the answers

What do living objects have that detect forms of energy from the world around them?

Sensors Signup and view all the answers

What is the term for the reaction of the organism to the stimulus?

Response Signup and view all the answers

What happens when the internal environment of the body is not maintained at a constant state?

You could become ill or even die Signup and view all the answers

What is the primary function of the endocrine glands?

To produce and regulate hormones Signup and view all the answers

What is the relationship between the endocrine system and homeostasis?

The endocrine system regulates homeostasis Signup and view all the answers

What is the term used to describe the process of maintaining a constant internal environment?

Homeostasis Signup and view all the answers

What is the process where particles in a liquid escape to form a gas?

Evaporation Signup and view all the answers

What happens to the particles in a gas as it is cooled?

They move slower Signup and view all the answers

What is the result of particles in a liquid coming together to form a liquid droplet?

Condensation Signup and view all the answers

What is necessary for a substance to change from one physical state to another?

A gain or loss of heat energy Signup and view all the answers

What happens to the particles in a solid as the temperature increases?

They vibrate more rapidly but remain in a fixed position Signup and view all the answers

What is the state of matter where particles have the highest energy?

Gas Signup and view all the answers

What holds particles together in a liquid?

A small amount of attraction between particles Signup and view all the answers

What happens to the particles in a liquid as they are cooled during freezing?

They slow down and lose energy Signup and view all the answers

What determines the amount of space an object takes up?

Its volume Signup and view all the answers

What are the three main states of matter on Earth?

Solid, Liquid, Gas Signup and view all the answers

What is the term for the smallest particle that all matter is made of?

Atom Signup and view all the answers

How many electrons can the first shell of an atom hold?

2 Signup and view all the answers

What is formed when two or more different types of atoms are bonded together?

Compound Signup and view all the answers

What is the term for the arrangement of atoms in an element?

Element Signup and view all the answers

What is the purpose of the atomic number of an element?

To determine the number of protons in the nucleus Signup and view all the answers

What is the term for a group of atoms bonded together?

Molecule Signup and view all the answers

What is the location of protons and neutrons in an atom?

In the nucleus Signup and view all the answers

What is the maximum electron capacity of the 2nd shell?

8 Signup and view all the answers

What is the term for a substance made up of only one type of atom?

Element Signup and view all the answers

What is the charge of an electron?

Negative Signup and view all the answers

What is the term for a group of atoms bonded together?

Molecule Signup and view all the answers

What determines the identity of an element?

Number of protons Signup and view all the answers

What is the role of the endoplasmic reticulum in protein synthesis?

Folding and modification of proteins Signup and view all the answers

What is the function of chloroplasts in plant cells?

Photosynthesis Signup and view all the answers

What is the fundamental unit of life?

Cell Signup and view all the answers

What is a common characteristic of plant and animal cells?

They contain membrane-bound organelles Signup and view all the answers

What is the third principle of the cell theory?

All cells come from pre-existing cells Signup and view all the answers

What is a way to classify living organisms?

Based on their cell structure Signup and view all the answers

What is a characteristic of unicellular organisms?

They are single-celled organisms Signup and view all the answers

What is the maximum number of electrons that can occupy the third shell of an atom?

18 Signup and view all the answers

What is the principle that states that electrons occupy the lowest available energy level?

Aufbau Principle Signup and view all the answers

What is the term used to describe the arrangement of electrons in an atom's electron shells?

Electron Configuration Signup and view all the answers

What is the capacity of the first shell of an atom?

2 Signup and view all the answers

What is the term used to describe the energy levels that electrons occupy around the nucleus of an atom?

Electron Shells Signup and view all the answers

What determines the element of an atom?

The number of protons in the nucleus Signup and view all the answers

What is the maximum number of electrons that can occupy the third shell?

18 Signup and view all the answers

What determines the arrangement of elements in a periodic table?

Atomic number Signup and view all the answers

Which part of an atom has a positive charge?

Proton Signup and view all the answers

What is the outermost energy level of an atom called?

Electron shell Signup and view all the answers

What is the term for the number of protons and neutrons in an atom's nucleus?

Mass number Signup and view all the answers

Study Notes

Electron Shells

Electron shells are the energy levels that electrons occupy around the nucleus of an atom.
Each shell has a specific capacity, and electrons fill the lowest available energy level first.
The first shell has a capacity of 2 electrons, the second shell has a capacity of 8 electrons, and the third shell has a capacity of 18 electrons.
Electron shells are also referred to as energy levels or orbitals.

Electron Configuration

Electron configuration is the arrangement of electrons in an atom's electron shells.
Electron configuration is typically written in a shorthand notation, with the number of electrons in each shell separated by commas.
The Aufbau principle states that electrons occupy the lowest available energy level.
The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of quantum numbers.
Electron configuration is important in determining the chemical properties of an element, such as its reactivity and bonding behavior.
Electron configuration of an atom can be determined by using the periodic table and the following rules:
- The first two columns of the periodic table (Groups 1 and 2) have a valence shell configuration of ns^1 or ns^2.
- The next six columns (Groups 13 to 18) have a valence shell configuration of ns^2 np^1 to ns^2 np^6.
- The transition metals (Groups 3 to 12) have a valence shell configuration of ns^1 to ns^2 (n-1)d^1 to (n-1)d^10.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about electron shells, their capacities, and the arrangement of electrons in atoms, also known as electron configuration.