) Elements with seven valence electrons are called   A. halogens   B. alkaline   C. noble gas   D. metals   E. alkali earth

Q: Balance the following equation: 40 20 40 K K Ca+? 19

A:

Q: 2. Consider radium, which has a half-life of 1620 years. How many atoms of radium will decay in 5 s…

A: We have a Radium sample of mass m=15 g=0.015 kg which has a molar mass of M=226 kg and half life of…

Q: Explain the mechanism of nature on how other elements higher than Iron is being formed.

A:

Q: Explain what makes the elements different from each other.  Why is gold different than carbon?

A: Different elements have different properties ( physical and chemical ).  In physical properties,…

Q: Question 3/ Calculate the density of the nuclear substance of the nucleus of the Carbon-12 atom, if…

A:

Q: Question 6 Groups on the Periodic Table contain elements with similar chemical properties because –…

A: Answer :-- They have same number of valence electrons. Because :- The Vertical column on the…

Q: 5. Which diode model represents the most accurate approximation?

A: SOlution: which diode model represent the accurate approximation.

Q: Size and Mass of a Hydrogen Atom

A: The mass of an atom shows how closely the constituents are packed in a given volume, whereas size…

Q: Which characteristic tells you an element is likely a non-metal? Has a shiny/metallic luster Not a…

A: Which characteristic tells you an element is likely a non-metal  .The non-metals are elements on the…

Q: Q1/ In an atom the number of electrons in 3rd shell is equal to the number of electrons in the 2nd…

A: Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: 1. What is the state of this atom? 3D2 Ground state Altered Excited Reactive

A: Note: only one question can be answered at a time. As shown in the figure 2 electrons in first orbit…

Q: Explain a couple of differences between the model of an atom with the nucleus sitting in the center…

A: Atom consists of nucleus sorrounded  with electron's

Q: Both statements are true.  Both statements are false.  First statement is true and second is false…

A: Answer:- Both statements are true.    Statements 1. To maintain electric neutrality, an atom must…

Q: 3. The discovery of the neutron helped people understand A. how two atoms of the same element can…

A:

Q: Complete the following diagrams below.

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Q: 2. (Principle) What does the H-value mean? How is it related to energy balance?

A: The H-Value means enthalpy value in thermodynamics.The Enthalpy value in thermodynamics is the sum…

Q: 1. Which of the following statements about the atomic nucleus are correct? (There may be more than…

A: about nucleus

Q: true or false why? 4. Harmonic oscillator model does not provide explanation for dissociation of…

A: 1. Harmonic oscillator model does not provide explanation for dissociation of molecules This…

Q: 17. The atomic energy level diagram accounts for A. the emission spectra of an atom B. the…

A: Energy level diagram

Q: 4. Most metals are NOT * O Ductile. O Malleable. O Liquid at room temperature. O Good conductors of…

A: The material that conducts heat and electricity are known as metals. The materials that do not…

Q: Jesus sketched models of two different netural isotopes of sodium. If the isotope models are…

A: Introduction: Electrons are the elementary particles of the matter. Electrons cannot be divided…

Q: P = P = P = Al N = N = N=- E = E = Bohr Diagram o Bohr Diagram eod Bohr Diagram Al F Lewis Structure…

A: ZXA is symbol of an element X. Where , Z = atomic number= proton no A= mass number = proton no +…

Q: 2. What are metalloids? a. the metal elements with small atomic numbers b. the elements between…

A: Correct answer is b) the elements between metals and nonmetals on periodic table. Explanation: A…

Q: What is the approximate mass of an oxygen molecule, O2, if the atomic mass of oxygen is 15.9994 u?

A: Let M denotes the approximate mass of an oxygen molecule, and Z denotes the atomic mass. Therefore,…

Q: Question 15 The half-life of Unobtanium-118 is 3 days. How many days pass for 800 grams of this…

A:

Q: 2. Explain the interactions between non-bonded atoms in molecular mechanical methods (Non-bonded…

A: Non bonded particle :not involving a chemical bond nonbonded interactions also : nonbonding…

Q: List three subatomic particles. Discuss their charges and positions in an atom.

A: Subatomic particles The subatomic particles are  1.Electron 2.Proton 3.Neutron

Q: This is NOT graded.

A:

Q: 3. Which atomic property is important in understanding charging by friction? * A. atomic mass B.…

A: Atomic property is important in understanding charging by friction is

Q: Aluminum 1 Germanium 2 Hard rubber 3 Glass 4

A: To determine: From the given options, which is a conductor material

Q: 1. Consider cobalt-60 (60Co) with a half-life of 5.25 years. How many years will it take for its…

A: Given, Half life of Co-60 is 5.25years

Q: What is metal

A: Metals are natural compounds of earth's crust, in which they are generally found in the forms of…

Q: 2. How is enthalpy related to energy?

A: Enthalpy is defined as amount of heat (energy) absorbed or released by the system to cause a change…

Q: The temperature near the surface of the earth is 291 K. A xenon atom (atomic mass = 131.29 u) has a…

A:

Q: 6. Find at least 5 elements whose symbols do not match their names 7. What are the two letters not…

A: Elements A substance that cannot be broken down into simpler substances by chemical means. An…

Q: Explain how you can use the specific heat to determine the identity of metals.

A:

Q: 1. Match the parts of an atom in the left column with all the phrases in the right column that…

A: from the basic atomic structure we know that electrons , protons and neutrons made up an atom…

Q: An oxygen-16 ion that has gained two valence electrons (anion net charge -2) and has a mass of…

A: Force acting on charged particle q moving with velocity v in a magnetic field B is given by,…

Q: 1. Everything in the universe is made of Your answer 2. The elements in the universe are listed on a…

A: 1- everything in  the universe is made up of matter, except energy. we know matter is made up of…

Q: Number of valencies in an Oxygen atom

A: The valency of an atom depends on the number of valence electrons in that atom. It is defined as the…

Q: An atom of carbon-14 isotope has more protons than an atom of carbon-12 isotope. True False

A:

The Bohr model

Students often get confused between Rutherford’s model and Bohr model of an atom. They interpret the postulates of both these models to be the same, which is incorrect. Rutherford’s model differs from Bohr’s model in the following ways: