#' @title The first 118 chemical elements
#'
#' @description The first 118 elements, ordered by atomic number.
#'
#' Some values of density, melting point,and boiling point are predictions
#' rather than measurements. For those elements which do not have any stable
#' nuclides, the mass number given is that of the longest-lived isotope
#' (exceptions here are bismuth, thorium, protactinium, and uranium standard
#' atomic weights are available). See the source for more detail.
#'
#'
#' @format A data frame with 118 rows and 17 variates:
#' \describe{
#' \item{Number}{The atomic number. The number of protons found the nucleus of every atom of the element.
#' It is the (positive) charge number of the element's nucleus.}
#' \item{Symbol}{One or two letter atomic symbol for the element.}
#' \item{Name}{Name of the element.}
#' \item{Group}{Identifies elements having similar chemical behaviours.
#' For most elements, the column in the periodic table is identical to the group.}
#' \item{Period}{Period identify a collection of elements of sequential mass typically from metals to nonmetals.
#' For most elements, period identifies its row in a periodic table.}
#' \item{Mass}{Relative atomic mass or atomic weight.
#' It is a dimensionless physical quantity defined
#' as the ratio of the average mass of atoms of a chemical element
#' in a given sample to the atomic mass constant.
#' Measurements are in unified atomic mass units or Daltons.
#' Expressed in these units, it is within 1 percent of the mass number.}
#' \item{Mass_number}{Total number of protons and neutrons in the atomic nucleus.}
#' \item{Density}{Element density in grams per cubic centimetre. }
#' \item{Melting_point}{Temperature in degrees Kelvin at which the
#' element changes state from solid to liquid.
#' Marked as approximate for Flerovium and Oganesson.}
#' \item{Boiling_point}{Temperature in degrees Kelvin at which the
#' element changes state from liquid to vapour.}
#' \item{Specific_heat_capacity}{The amount of heat energy required
#' to increase the temperature by one Kelvin degree measured in Joules
#' per gram and degree Kelvin.}
#' \item{Electro_negativity}{The tendency of an atom to attract a shared pair of
#' electrons (or electron density) towards itself. The higher the number
#' the greater the attraction.}
#' \item{Abundance}{The estimated abundance of the element in the
#' Earth's crust in millograns per kilogram.
#' For Technetium and Francium the value is marked
#' as approximate; for Neptunium and Plutonium the value
#' is an upper bound.}
#' \item{Category}{Identifies where elements lie on the
#' metal - metalloid - nonmetal categorization.}
#' \item{Subcategory}{Identifies the subcategory of the element on the
#' metal - metalloid - nonmetal categorization.}
#' \item{x}{The geometric horizontal position in the periodic table where this element appears.}
#' \item{y}{The geometric vertical position in the periodic table where this element appears.}
#' }
#'
#' @docType data
#'
#' @name elements
#'
#'
#' @keywords elements atoms atomic molecule
#'
#' @author R.W. Oldford
#'
#' @source Data extracted from Wikipedia's "List of chemical elements" \url{https://en.wikipedia.org/wiki/List_of_chemical_elements} (April 17, 2020).
NULL
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.