By studying a star's spectrum, scientists can work out its chemical make-up and temperature. What instrument do astronomers' use to carry out this task?

A) space probe

B) spectroscope

C) radio telescope

D) light telescope

The Balmer series, named after Johann Balmer, is a portion of the hydrogen emission spectrum produced from the transitions between the n=2 energy level and higher energy levels.

How many moles of NO2 will form when 3.3 moles of Cu are reacted with excess HNO3?

Which of these is an example of a wetland area? A. marsh B. stream C. city park D. farm land

An airplane can fly at a height of 12.5km over the ground. How high is this in centimeters

Which one of the following is a redox reaction? Al3 + (aq) + PO43 - (aq) → AlPO4 (s) NaCl (aq) + AgNO3 (aq) NaNO3 (aq) + AgCl (s) 3Mg (s) + 2FeCl3 (aq) → 3 MgCl2 (aq) + 2Fe (s) LiCl (aq) + AgCH3CO2 (aq) → AgCl (aq) + LiCH3CO2 (aq) HF (aq) + KOH (aq)

Ocean constitutes most of ___ of water a) Evaporation b) Precipitation c) Condensation d) Transpiration e) Sublimation Don't choose a random letter.

In the reaction, Zn + HCl-> ZnCl2 + H2, 25 grams Zn are reacted with 17.5 grams HCl. How many grams of H2 will be produced? A. 0.382 g of H2 B. 0.479 g of H2 C. 0.7865 g of H2 D. 0.484 g of H2

Is nail varnish soluble?

What is the periodic trend for atomic size from top and bottom in a group? From left to right in a period?

Which planets' orbits is the belt located between the main asteroid belt?