radioactive elements
Second grade !
The average reading level for a second grade student in the United States is 1.4 to about 2.4. This means that most second grade students are reading at high first grade levels or medium second grade levels.
2nd grade mid year
Yes, you should capitalize "Second Grade" when referring to a specific grade level in a sentence, as it is a proper noun.
An example of a figurative sentence on a second grade level is "I'm so hungry, I could eat a horse." It contains hyperbole.
Childen at second grade level are eight year's old
Yes, grade level is categorical data because it represents distinct categories or groups such as first grade, second grade, etc. It cannot be measured on a numerical scale and has no inherent order.
It is 10th grade. Each letter goes with the grade, so A is first, B is second so on.
Marie Curie discovered radium and polonium and made huge inroads in the research of radioactivity and it's benefits. As a note of interest, both her and her husband Pierre's journals are still radioactive.
No, "second grade" is not a proper noun. It refers to a specific level or year of education and is not a specific or unique person, place, or thing.
1000
The atom is neutral; the cations of Po are of course positive. Polonium lose electrons.