Answer:b.CaCl2
Explanation:
A compound is a substance resulting when two or more elements are are chemically bonded together either ionically or covalently in a fixed ratio.
From the given options we can see that the only compound there is CaCl2 which is an ionic compound in the fixed ratio of one calcium ion to two chloride ions.
Other options , Cu,Na and Nd are merely pure substance---Elements
<span>The answer is D) 108 million kilometers. To solve this problem, you must perform a simple unit conversion calculation. 1 AU = 150,000,000 km is the conversion factor. Take the radius of Venus, .72 AU, and multiply it by 150,000,000 km/1 AU. You flip the conversion factor so that the units of the original distance in the numerator cancel the units in the denominator of the conversion factor. completing the calculation gives you 108,000,000 km</span>
The only chemical that is a liquid at room temperature is Mercury. It's toxic, and has a high vapor pressure at room temperature.
CH4+(x)O2=CO2 +(Y)H2O
C=1 +H=4 +O=? = C=1 +O=2+? +H=?
H=4>>Y=2
C=1 +H=4 +O=? = C=1 +O=(2+2) +H=4
C=1 +H=4 +O=4 = C=1 +O=4 +H=4
O=4>>X=2
CH4+(2)O2 =CO2 +(2)H2O
Salad, a bag of different colored pebbles or sand, etc