Me i beg you i really need
elements on the periodic table appear together in regions ba...
Chemistry, 06.11.2019 21:31 bryanmcmillianjr
Me i beg you i really need
elements on the periodic table appear together in regions based on the energy sub-level that contains their outermost valence electrons. what are these regions called?
families
blocks
main-group elements
transition elements
mendeleev's periodic law has been restated to say that when the elements are arranged in order of increasing atomic number, there is a periodic pattern in their chemical and physical properties.
true
false
in 1894, william ramsey discovered the first of several non-reactive elements. which group of elements did ramsey discover that would alter the structure of the periodic table?
the transition metals
the noble gases
the halogens
the alkali metals
which of the following elements is man-made?
platinum
technetium
radon
cesium
what is the name of the group (family) that includes the elements radium, strontium, and magnesium?
noble gases
metals
alkaline earth metals
alkali metals
an element's atomic number is an indicator of its atom's:
number of protons
number of neutrons
charge
weight
an atom of oxygen contains 8 protons, 8 electrons, and 16 neutrons.
true
false
which of the following is not true of electronegativity?
generally increases as atomic radius decreases within a period
generally decreases as atomic number increases within a period
generally decreases as the principal energy level increases within a group
generally increases as atomic radius decreases within a group
which of the following elements possesses the most valence electrons?
argon
fluorine
helium
plutonium
how many dots should be drawn around the symbol, c, to create the lewis dot structure for a carbon atom?
two
four
six
eight
to achieve an octet in the valence energy level, a nitrogen atom will lose five electrons.
true
false
to achieve an octet in the valence energy level, a sulfur atom will become a cation.
true
false
Answers: 3
Chemistry, 21.06.2019 22:30
Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution? a. 3.88 m, b. 1.03 m, c. 1.5 m, d. 15.5 m
Answers: 3
Chemistry, 22.06.2019 20:10
The lattice enthalpy (formation of ionic solid from ions in the gas phase) for agcl(s) is -916 kj/mol and the hydration enthalpy (dissolution of gaseous ions into water) is -850 kj/mol. how much heat (in joules) is involved in forming 1l of saturated agcl solution (1.8 × 10-4 g / 100 ml water) by dissolving agcl(s)? assume solution volume does not change much upon dissolution. the equations are given below. ag+(g) + cl−(g) æ agcl(s)
Answers: 3
Chemistry, 23.06.2019 05:30
The image compares the arrangement of electrons in two different neutral atoms. a figure labeled atom q has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has six black spheres. to the left of this figure is another figure labeled atom p. atom p has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has seven black spheres. which of the following best explains the position of the two atoms in the periodic table? atom p has an estimated zeff of 7 and is therefore to the left of atom q, which has a zeff of 6. atom p has an estimated zeff of 7 and is therefore to the right of atom q, which has a zeff of 6. atom p has an estimated zeff of 5 and is therefore below atom q, which has a zeff of 4. atom p has an estimated zeff of 5 and is therefore above atom q, which has a zeff of 4.
Answers: 3
Chemistry, 23.06.2019 09:10
A155.0 9 piece of copper at 182 °c is dropped into 2500 g of water at 23.9 °c. (the specific heat of copper is 0.385 1/9°c.) calculate the final temperature of the mixture. (assume no heat loss to the surroundings.)
Answers: 2
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