Flashcards
Chem - Elements and Atoms
Cards in this deck (17)
- 1What is Element?Elements are the simplest pure substances, and they cannot be broken down into any substances.
- 2Why elements are often called building blocks of matters?It is because all matter is composed of one element or a combination of two or more elements.
- 3What is compound?A compound is a pure substance made of two or more elements that are combined chemically in a specific ratio
- 4What is mixture?A mixture is two or more substances - elements, compounds, or both - that are in the same place but are not chemically combined.
- 5What is atom?It is the smallest particle of an element
- 6What is Scientific theory?Scientific theory is a well-tested idea that explains and connects a wide range of observations
- 7Dalton's ideas 1. All elements are composed of atoms that..cannot be divided
- 8Dalton's ideas 2. All atoms o the same element are exactly aike and have the same mass...atoms of different elements are different and have different masses.
- 9Dalton's idea 3. An atom of one element cannot be changed into an atom of a different element.Atoms cannot be created or destoryed in any chemical change, only rearranged
- 10Dalton's ideas 4. Every compound is composed of atoms of different elements,...combined in a specific ratio
- 11Thomson model An atom is consisted of negative charges scattered throughout a ball of positive charge. What are those negatively charged particles?electrons
- 12Rutherford inferred that an atom's positive charge must be clustered in a tiny region in its center, What do we call this tiny region?Nucleus
- 13Work by other scientists later suggested that the nucleus was made of one or more positively charged particles. What did Rutherford name the positively charged particles in the nucleus of an atom?protons
- 14A cloud of Electrons An electron's movement is related to its _______ . Electrons having higher energy are more ____________ by the nucleus than are electrons having lower energy.energy level
loosely held - 15In 1932, James Chadwick discovered another particle in the nucleus of atoms. What is it? why is this new particle hard to detected?Neutron. It was hard to detected because it was electrically neutral
- 16What are valence electrons?Valence electrons are those electrons that have the highest energy level and are held most loosely.
- 17What does the number of valence electrons oin an atom of an element determine?The number of valence electrons in an atom of an element determines many properties of that element, including the ways in which the atom can bond with other atoms.
Information
- Description
- Flashcards on Chem - Elements and Atoms, created by DanielTimmyChow on 28/04/2015.
- Created by
- DanielTimmyChow
- Views
- 3
- Tags
- Rating