Which of the folowing is true about radio waves?

☹They have short wavelenghts

☹They can penetrate dust clouds

☹They reveal hot gases

☹They have high energies

What does the number on the top left of the symbol show?

Which one of the following ia a characteristic of a metal?

A sample of He gas (V = 3.0 L) at 5.6 atm and 25 °C was combined with 4.5 L of Ne gas at 3.6 atm and 25 °C in a 9.0 L flask (which was initially evacuated). What is the total pressure in the 9.

What is the charge of hydroxide

Solutions A have a uniform composition and can be separated by physical means B cannot be separated by physical means C do not have a uniform composition D are none of the above

If the age of the middle layer of a rock sample is between 600 million years and 1 billion years, which of the following could be the age of the topmost layer?

All of space and the matter in it is?

Which compounds has the lowest vapor pressure at 50 c

An incomplete chemical equation is given here. Which set of numbers, placed in the blanks as the coefficients, will balance the equation shown? __HCl + __Na2CO3 → __H2CO3 + __NaCl 1, 2, 1, 2 2, 1, 2, 1 2, 1, 1, 2 2, 2, 1, 1

What element has 6 protons and 8 neutrons?