Grade 8 Science: Matter in Chemistry

Which of the following best defines an element?

A pure kind of matter that cannot be broken down into simpler substances by ordinary chemical means

What is the composition of water (H2O) according to the text?

Hydrogen and Oxygen in a ratio of 2:1 by weight

What is the mass of an electron compared to a hydrogen atom?

1/1837 times the mass of a hydrogen atom

How are compounds different from elements?

Elements are made up of similar kinds of atoms, while compounds are formed by the chemical combination of two or more elements Signup and view all the answers

What is the charge of a neutron?

Neutral Signup and view all the answers

What is the mass of an electron in terms of atomic mass unit (amu)?

1/1837 amu Signup and view all the answers

In an electrically neutral atom, what is the relationship between the number of protons and electrons?

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

What is the unit of measuring electric charge?

Coulomb Signup and view all the answers

What property do electrons and protons possess in terms of charge?

Electrons carry negative charge, protons carry positive charge Signup and view all the answers

What is the atomic number of an element defined as?

Number of protons only Signup and view all the answers

What is an element defined as in chemistry?

A pure form of matter that cannot be broken down by ordinary chemical means Signup and view all the answers

What are compounds formed by?

The chemical combination of two or more elements in a fixed proportion Signup and view all the answers

What are atoms composed of?

Electrons, protons, and neutrons Signup and view all the answers

What is the mass relationship between an electron and a hydrogen atom?

Mass of an electron is 1/1837 times the mass of a hydrogen atom Signup and view all the answers

What is the charge of an electron?

Negative charge Signup and view all the answers

Which subatomic particle is located in the nucleus of an atom?

Neutron Signup and view all the answers

What is the mass of a neutron compared to a hydrogen atom?

Equal Signup and view all the answers

What is the atomic mass of Boron (B) based on the given information?

11 Signup and view all the answers

How is the electric charge in an atom neutralized?

By balancing the positive charge of protons with the negative charge of electrons Signup and view all the answers

What property allows for the electrically neutral state of an atom?

Balance of protons and electrons Signup and view all the answers