Answer:
Explanation:
Group Most Likely Ionic Charge Number of Valence Electrons
I +1 1
II +2 2
III +3 3
IV +4 or -4 4
V -3 5
VI -2 6
VII -1 7
VIII 0 8
For elements in group IV and above, their ionic charge is (8-number of their valence electrons.)
Answer:
<em>The flow of thermal energy in a system, at constant atmospheric pressure AND at thermodynamic standard temperature and pressure.</em>
Answer:
See explanation
Explanation:
Precision means the reputability of measurement and accuracy means how close a measurement is to the actual value. To get the measured mass of the acetone we need to substract the mass of the bottle from the measured mass of bottle and acetone.
The mass of the bottle is 38.0015g
⇒The mass of acetone in bottle 1= 0.7783g
⇒Mass of acetone in bottle 2= 0.7780g
⇒Mass of acetone in bottle3= 0.7786g
The measured value is near to each other. ⇒ the measurements are <u>precise</u>.
To check the <u>accuracy</u> we can compare the average value to the actual mass of the acetone.
Average of the acetone measurement is (0.7783+0.7780+0.7786)/3 = 0.7783g
The percentage of difference of the average measurement to the actual mass is = {(actual value-measured value)/actual value}x100%
={(0.7791-0.7783)/0.7791}x100%
=0.10%
So we can see the difference is very small ⇒ the measurement is accurate.
DDT was one of the first chemicals in widespread use as a pesticide.
<span><span>Food supplies: USDA found DDT breakdown products in 60% of heavy cream samples, 42% of kale greens, 28% of carrots and lower percentages of many other foods.</span><span>Body burden: DDT breakdown products were found in the blood of 99% of the people tested by CDC.</span><span>Health impacts: Girls exposed to DDT before puberty are 5 times more likely to develop breast cancer in middle age, according to the President’s Cancer Panel.</span></span>
