Q1.Week1b.Explain-how-the-concept-of-atomic-number-led-to-the-synthesis-of-new-elements-in-the-laboratory.pptx

physical science

1. Directions: Read the passage below TWICE and UNJUMBLE the letters of the enclosed words to create meaningful statements. When Mendeleev put his periodic table together, nobody knew about the existence of the (1. ncleusu ). It was not until 1911 that Rutherford conducted his gold foil experiment that demonstrated the presence of it in the atom. In 1913, English physicist Henry Moseley (1887-1915) examined x-ray spectra of a number of chemical elements.

2. He would shoot X-rays through crystals of the element and study the (2. walengveth ) of the radiation he detected. Moseley found that there was a relationship between wavelength and (3. atocim ) number. His results led to the definition of atomic number as the number of (4. sporton ) contained in the nucleus of each atom. He then realized that the elements of the periodic table should be arranged in order of increasing atomic (5. umbren ) rather than increasing atomic (6. ssam ).

3. Mendeleev and Moseley are credited with being most responsible for the modern (7. diperico ) law: When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical (8. tesiperpro ). Each new horizontal row of the periodic table corresponds to the beginning of a (9. rioped ) because a new principal (10. neregy ) level is being filled with (11. stroenlec ). Elements with similar chemical properties appear at regular intervals, within the vertical columns called (12. progu ).

4. Concept of Atomic Number Led to the Synthesis of New Elements in the Laboratory

5. Concept about Atom You learned earlier how all matter in the universe is made from tiny building blocks called atoms. All modern scientists accept the concept of the atom, but when  the concept of the atom was first proposed about 2,500  years   ago,ancient  philosophers laughed at the idea. 

6. Concept about Atom   It  has always been difficult  to convince people of the existence of things that are too small to be seen.

7. Henry Moseley He was  an English physicist whose experiment demonstrated that the major properties of an element are determined by the atomic number, not by the atomic weight, and firmly established the relationship between atomic number and   the charge of the atomic nucleus.

8. Henry Moseley Henry Moseley was a researcher at Rutherford’s laboratory . In 1913, Moseley used Rutherford’s work to advance the understanding of the elements and solve the problem with Mendeleev’s periodic table.

9. Henry Moseley Explain that organizing the elements by their weight did not always give a periodic alignment of their chemical properties.

10. He also noticed that the frequency increased by a certain amount when the “positive charge” of the chosen element was higher. Moseley noticed that shooting electrons at elements caused them to release x-rays at unique frequencies.

11. Hypothesis that the elements’ atomic number, or place in the periodic table, was uniquely tied to their “positive charge”, or the number of protons they had.

12. Hypothesis This discovery allowed for a better arrangement of the periodic table, and predicted elements that were not yet discovered.

13. Subatomic particles are the individual protons, neutrons, and electrons that make up the composition of atoms. The number of protons, neutrons, and electrons in an atom can be determined from a set of simple rules. ● The number of protons in the nucleus of the atom is equal to the atomic number (Z). ● The number of electrons in a neutral atom is equal to the number of protons.

14. ● The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. ● The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

15. Which element has a greater number of protons - Potassium (K) or Selenium (Se)?

16. Which element has a greater number of protons - Potassium (K) or Selenium (Se)? K has 19 protons and Se has 34.

17. Number of Protons is equal to the elements’ atomic numbers .

18. 2 . Which element has a smaller number of electrons - Copper (Cu) or Silver (Ag )?

19. 2 . Which element has a smaller number of electrons - Copper (Cu) or Silver (Ag )? Cu has 29 electrons, and Ag has 47 electrons.

20. The number electron (in a neutral atom) is equal to the number of protons.

21. 3. Which element has a greater number of neutrons – Magnesium (Mg) or Tin (Sn)?

22. 3. Which element has a greater number of neutrons – Magnesium (Mg) or Tin (Sn)? Mg has 12 neutrons and Sn has 69.

23. Calculated by subtracting the atomic number from the atomic mass (rounded to a whole number).

24. Element Name Element Symbol Atomic Number Atomic Mass # of Protons # of Electrons # of Neutrons Helium He 2 4 2 2 2 Titanium O 1. 2. 3. 4. 5. Fe 6. 7. 8. 9. 10. 11. 12. 18 13. 14. 15. 16. Sulfur S 17. 18. 16 19. 20.