1. Who was the first person to create a periodic table? When? 2. What is the modern periodic table?

3. Compare and contrast the periods and groups of the modern periodic table.

4. In the modern periodic table (found in the back of your agenda), find the element named lead (Pb). How many protons do atoms of lead have? To which class of elements does lead belong?

5. Most of the elements on the periodic table belong to what class of elements.

6. Which groups of the modern periodic table contain elements that are classified as metalloids?

Your 249 ml cup of coffee is too hot to drink when served at 82 degree celsius. what is the mass of an ice cube taken from a -21 degree celsius freezer, that will cool your coffee to a pleasant 54 degree celsius. specific heat of the water is 4190 j/kg c, specific heat of ice is 2090 j/kg c, heat of fusion of ice is 3.33 x 10^5 j/kg

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

Mga halaman/punong ornamental na di namumulaklak